Basic Engine Troubleshooting

Troubleshooting can be difficult. The Troubleshooting Index gives a list of possible problems. To make a repair to a problem, see the possible cause and corrective action on the pages that follow. Also, check the 3176C & 3196 Electronic Troubleshooting, SENR1180.

This list of problems, causes and corrections will only give an indication of where a possible problem can be, and what repairs are needed.

Service personnel may remember similar complaints which were corrected by a previous method of troubleshooting. However, just because the complaint is the same the cause for the complaint can be different.

Be sure to get a good description of the problem from the operator and/or the person who owns the vehicle. What they tell you about the problem can save you time and make the repair job faster and easier.

Introduction

NOTE: For Specifications with illustrations, make reference to Specifications For 3176C & 3196 Industrial Engine, SENR1172. If the Specifications in SENR1172 are not the same as in the Systems Operation, Testing & Adjusting, look at the printing date on the front cover of each book. Use the Specifications given in the book with the latest date.

Troubleshooting Problem List

1. Loud Combustion Noise 45

2. Fuel Consumption Too High 45

3. Too Much Black Or Gray Smoke 46

4. Too Much White Smoke 46

5. Too Much Blue Smoke 46

6. Engine Has Low Oil Pressure 46

7. Engine Overheating 47

8. Engine Excessive Cooling 48

9. Coolant Leaks Outside Of Engine 48

10. Coolant Leaks At The Overflow Tube 48

11. Coolant Leakage Inside Engine 48

Troubleshooting Problems

Problem 1: Loud Combustion Noise

Probable Cause:

1. Poor Quality Or Water In Fuel

Follow the recommendations given in Special Instruction, SEHS7067, Fuel Recommendations For Caterpillar Diesel Engines. Also, Special Instruction, SEHS6947 has fuel correction factors and tables.

2. Wrong Timing Position Sensor Calibration

Refer to 3176C & 3196 Electronic Troubleshooting, SENR1180.

Problem 2: Fuel Consumption Too High

Probable Cause:

1. Fuel Consumption Errors

Follow high fuel consumption check list:

* Fuel measured correctly

* Comparison to other industrial applications

* Different engine specifications

* Different operating loads

* Different operating modes

2. Poor Quality Or Water In Fuel

Follow the recommendations given in Special Instruction, SEHS7067, Fuel Recommendations For Caterpillar Diesel Engines. Also, Special Instruction, SEHS6947 has fuel correction factors and tables.

3. Fuel System Leaks

Inspect the fuel system for leaks and make repairs or replacements as needed.

4. Excess Idle Time

Shut engine off when not in use.

5. Fuel And Combustion Noise (knock)

Refer to 3176C & 3196 Electronic Troubleshooting, SENR1180.

6. Wrong Timing Position Sensor Calibration

Refer to 3176C & 3196 Electronic Troubleshooting, SENR1180.

Problem 3: Too Much Black Or Gray Smoke

Probable Cause:

1. Not Enough Air For Combustion

Check for a plugged air cleaner element or blockage in the air lines. Follow the procedures in the Testing & Adjusting section to check inlet manifold pressure and aftercooler core leakage.

2. Wrong Timing Position Sensor Calibration

Refer to 3176C & 3196 Electronic Troubleshooting, SENR1180.

Problem 4: Too Much White Smoke

Probable Cause:

1. Too Much Oil In Engine

Do not put too much oil in the crankcase. If the oil level in the crankcase goes up as the engine is used, check for fuel in the crankcase. Make repairs or replacements to the fuel injection lines and unit injectors as needed to keep fuel out of the crankcase.

2. Engine Misfires Or Runs Rough

Check items listed in Problem No.3. Refer to 3176C & 3196 Electronic Troubleshooting, SENR1180.

3. Wrong Timing Position Sensor Calibration

Refer to 3176C & 3196 Electronic Troubleshooting, SENR1180.

4. Coolant In Combustion System

Coolant in the combustion chamber can cause white smoke. A cracked cylinder head or liner, also a defective cylinder head gasket are possible causes for this condition.

Problem 5: Too Much Blue Smoke

1. Failed Turbocharger Oil Seal

Check inlet manifold and aftercooler core for oil. Make a repair or replacement of the turbocharger as needed.

2. Worn Valve Guides

See the Specifications module for the maximum permissible wear of the valve guides.

3. Worn Piston Rings

Worn piston rings and/or cylinder walls can be the cause of blue smoke and can cause a loss of compression. Make a visual inspection of the cylinder walls and piston rings. If necessary, measure the cylinder walls and piston rings. For the cylinder and piston ring specifications, see the Specifications module. NOTE: High wear at low hours is normally caused by dirt coming into the engine with the inlet air.

Problem 6: Engine Has Low Oil Pressure

Probable Cause:

1. Low Engine Oil Level

Check engine oil level and fill to proper level.

2. Oil Leaks

Check for loose oil filter or oil supply lines, etc.

3. Dirty Oil Filter Or Cooler Core

Check the operation of bypass valve for the filter. Install new oil filter elements if needed. Clean or install new oil cooler core. Remove dirty oil and fill the engine with clean oil to the correct level.

4. Diesel Fuel In Lubricating Oil

Find the place where diesel fuel gets into the lubrication oil. Make repairs as needed. Remove any oil that has diesel fuel in it. Install new oil filters and fill the engine with clean oil to the correct level.

5. Too Much Clearance Between Rocker Arm Shaft And Rocker Arms

Check for correct lubrication in valve compartment. Install new parts as necessary.

6. Oil Pump Suction Pipe Has A Defect.

Replacement of the pipe is needed.

7. Relief Valve For Oil Pump Does Not Operate Correctly

Clean valve and housing. Install new parts as necessary.

8. Oil Pump Has A Defect

Make a repair or replacement of the oil pump as needed.

9. Too Much Clearance Between Camshaft And Camshaft Bearings

Install new camshaft and camshaft bearings if necessary.

10. Too Much Clearance Between Crankshaft And Crankshaft Bearings

Inspect the bearings and crankshaft journals and make repairs and replacements as necessary.

11. Too Much Bearing Clearance For Idler Gear

Inspect bearings and make replacements as necessary.

12. Piston Oil Cooling Jet Tubes Not Installed

Install piston oil cooling jet tubes.

13. Defective Oil Pressure Gauge

Replace oil pressure gauge

Problem 7: Engine Overheating

Probable Cause:

1. Low Coolant Level

If the coolant level is too low, not enough coolant will go through the engine and radiator. This lack of coolant will not take enough heat from the engine. Low coolant level is caused by leaks or wrong filling of the cooling system. With the engine cool, be sure the coolant can be seen in the heat exchanger tank.

2. Defective Temperature Gauge

A temperature gauge which does not work correctly will not show the correct temperature. If the temperature gauge shows that the coolant temperature is too hot but other conditions are normal, either install a gauge you know is good or check the cooling system with the 4C6500 Digital Thermometer Group.

3. Defective Hose(s)

Defective hoses with leaks can normally be seen. Hoses that have no visual leaks can "collapse" (pull together) during operation and cause a restriction in the flow of coolant. Hoses become soft and/or get cracks after a period of time. See Operation & Maintenance Manual for the frequency to change hoses. The inside of the hose can become loose, and the loose particles of can cause a restriction in the flow of coolant.

4. Defective Water Temperature Regulator

A regulator that does not open, or only opens part of the way, can cause above normal heating. See the Testing & Adjusting section for the procedure to test water temperature regulators.

5. Defective Water Pump

A water pump with a loose impeller does not pump enough coolant for correct engine cooling. A loose impeller can be found by removing the water pump, and by pushing the shaft back and pulling it forward. If the impeller has no damage, check the impeller clearance.

6. Air In Cooling System

Air can get into the cooling system in different ways. The most common causes are not filling the cooling system correctly, and combustion gas leaking into the system. Combustion gas can get into the system through inside cracks or defective cylinder head gaskets. Air in the cooling system causes a reduction in coolant flow and bubbles in the coolant. Air bubbles hold coolant away from engine parts, preventing heat flow.

7. Engine Used In A Lug Condition

"Lugging" (when the machine is used in a range too high for engine rpm to go up as the engine is accelerated or engine rpm goes down with engine at full throttle) the engine causes the engine rpm to be low. This low rpm causes a reduction in the flow of coolant through the system. This less coolant flow during high input of fuel will cause above normal heating.

8. Air Inlet Restriction

Restriction of the air coming into the engine causes high cylinder temperatures and more than normal amount of heat to pass to the cooling system. Check for a restriction with a water manometer or a vacuum gauge (which measures in inches of water). Connect the gauge to the engine air inlet between the air cleaner and the inlet to the turbocharger. With gauge installed, run engine at full load rpm and check the restriction. Maximum restriction of air inlet 635 mm (25 inches) of water. If the indication is higher than the maximum permissible restriction, remove the dirt from the filter element, or install a new filter element and check the restriction again. If the indication is still too high, there must be a restriction in the inlet piping.

9. Exhaust Restriction

Restriction in the exhaust system causes high cylinder temperatures and more than normal amount of heat to pass to the cooling system. To see if there is an exhaust restriction, make a visual inspection of the exhaust system. If no damage is found, check the system for back pressure from the exhaust (pressure difference measurement between exhaust outlet and atmosphere). The back pressure must not be more than 1016 mm (40 in) of water. You can also check the system by removing the exhaust pipes from the exhaust manifolds. With the exhaust pipes removed, start and run the engine to see if the problem is corrected.

10. Fuel Injection Timing Not Correct

Check and make necessary adjustments as given in the Testing & Adjusting section.

Problem 8: Engine Excessive Cooling

Probable Cause:

1. Long Idle Periods

When the engine is running with no load, only a small quantity of fuel is burned and engine heat is removed too fast.

2. Very Light Load

Very light loads, and a very slow speed can cause excessive cooling because of the low heat input of the engine.

3. Defective Water Temperature Regulator

A water temperature regulator that is "stuck" open (will not move to the closed position) will cause overcooling. A water temperature regulator that is stuck between the open and closed positions, or only opens part of the way, can cause overcooling. Also, coolant leaks around the water temperature regulator, such as vent lines, can cause overcooling.

Problem 9: Coolant Leaks Outside Of Engine

Probable Cause:

1. Leaks In Hoses Or Connections

Check all hoses and connections for visual signs of leakage. If no leaks are seen, look for damage to hoses or loose clamps.

2. Leaks In The Water Pump

Check the water pump for leaks before starting the engine, then start the engine and look for leaks. If there are leaks at the water pump, repair or install a new water pump.

3. Cylinder Head Gasket Leakage

Look for leaks along the surface of the cylinder head gasket. If you see leaks, install a new head gasket.

Problem 10: Coolant Leaks At The Overflow Tube

Probable Cause:

1. Defective Pressure Cap Or Relief Valve

Check the sealing surfaces of the pressure cap and the radiator to be sure the cap is sealing correctly. Check the opening pressure and sealing ability of the pressure cap or relief valve with the 9S8140 Cooling System Pressurizing Pump Group. Refer to Checking Pressure Cap in Testing & Adjusting Section.

2. Engine Runs Too Hot

If coolant temperature is too high, pressure will be high enough to move the cap off of the sealing surface in the radiator and cause coolant loss through the overflow tube. See Problem 7: Engine Overheating.

3. Cylinder Head Gasket Leakage Or Crack(s) In Cylinder Head Or Cylinder Block

Remove the radiator cap and, with the engine running, look for air bubbles in the coolant. Bubbles in the coolant are a sign of probable leakage at the head gasket. Remove the cylinder head from the engine. Check cylinder head, cylinder walls and head gasket surface of the cylinder block for cracks. When the head is installed, use a new head gasket, spacer plate gasket, water seals, and O-ring seals.

Problem 11: Coolant Leakage Inside Engine

Probable Cause:

1. Cylinder Head Gasket Leakage

If the cylinder head gasket leaks between a water passage and an opening into the crankcase, coolant will get into the crankcase.

2. Crack(s) In Cylinder Head

Crack(s) in the upper surface of the cylinder head, or an area between a water passage and an opening into the crankcase, can allow coolant to get into the crankcase.

3. Crack(s) In Cylinder Block

Crack(s) in the cylinder block between a water passage and the crankcase will let coolant get into the crankcase.

Electronic Control System

Diagnostic Codes

For an explanation of each diagnostic code see 3176C & 3196 Electronic Troubleshooting, SENR1180.

Active Diagnostic Codes

Diagnostic codes are used by the 3176C and 3196 System to warn the vehicle operator of a problem and indicate to the service technician the nature of the problem. Some codes are used only to record an event and do not indicate problems that need repair.

An Active diagnostic code represents a problem that should be investigated and corrected as soon as possible. Repairing the cause of an active code will cause the code to be cleared.

When an active code is generated, the diagnostic lamp will turn on and remain on, flashing every five seconds. If the condition generating the fault occurs only for a brief moment, the lamp will go off after five seconds and the code will be logged.

There are a few codes which are not a response to a performance problem, but merely record an event such as 01, 35, 41, 47 and 55. In these cases troubleshooting is not required.

Some Diagnostic Codes cause the 3176C and 3196 System to make major changes in engine operation or limits, as a result of the code being generated.

Logged Diagnostic Codes And Events

When the ECM generates a diagnostic code, it usually logs the code in permanent memory within the ECM. The ECM has an internal diagnostic clock and will record the hour Each time a code is logged. Knowing when and how often the code was generated can be a valuable indicator when troubleshooting intermittent problems. Logged codes can be retrieved or erased using an electronic service tool. They can be a valuable indicator when troubleshooting intermittent problems.

* Diagnostic Codes that are logged repeatedly may indicate a problem that needs special investigation. Codes that are logged only a few times and do not result in driver complaints, may not need attention until a scheduled maintenance interval.

To troubleshoot a Logged Diagnostic Code, refer to the "Troubleshooting Diagnostic Codes" section in Electronic Troubleshooting, SENR1180. If symptoms continue, refer to "Troubleshooting Without A Diagnostic Code" section in Electronic Troubleshooting, SENR1180.

* The most likely cause of an intermittent problem is a faulty connection or damaged wiring. Next likely is a component failure (sensor or switch for example). Least likely is the ECM itself.

Electronic Service Tools

The Caterpillar Service Tools for the 3176C and 3196 Electronic Control System are designed to help the service technician:

* Diagnose Faults And System Problems

* Calibrate Sensors

* Program Parameters

* Read Trip Data

* Read Status Of Sensors/Switches

The 3176C and 3196 Industrial Engine requires an Electronic Control Analyzer and Programmer (ECAP) or PC based Cat ET to communicate with the 3176C and 3196 Electronic Control Module.

Throttle Position Sensor Adjustment

The Throttle Position Sensor (TPS) is used to provide a throttle signal to the Electronic Control Module (ECM). Sensor output is a constant frequency signal whose pulse width varies with throttle position. This output signal is referred to as either "Duty Cycle" or a "Pulse Width Modulated (PWM)" signal and is expressed as a percentage. When correctly adjusted, the TPS will produce a "Duty Cycle" signal of 15 to 20 percent at the low idle throttle position and 80 to 85 percent at the maximum throttle position. This signal is translated by the ECM into a "Throttle Position" signal of three percent at low idle and 100 percent at maximum throttle.

Pedal Mounted Throttle Sensor

Pedal Mounted Throttle Sensor

The Pedal Mounted Throttle Sensor is mounted on the back of the OEM supplied pedal. No adjustments are required for the Pedal Mounted Throttle Sensor. Calibration of the Pedal Mounted Throttle Sensor is done automatically by the ECM. The correct calibration can be displayed with the electronic service tool. The correct percent throttle (governor control movement) is displayed as three percent with the throttle completely released, and 100 percent with the throttle completely depressed.

Rotary Position Throttle Sensor

Rotary Position Throttle Sensor

Calibration of the Rotary Position Throttle Sensor is done by the ECM. The correct calibration can be displayed with the electronic service tool. The correct percent throttle (governor control movement) is displayed as zero percent with the throttle completely released, and 100 percent with the throttle completely depressed.

Fuel System

Either too much fuel or not enough fuel for combustion can be the cause of a problem in the fuel system. Many times work is done on the fuel system when the problem is really with some other part of the engine. The source of the problem is difficult to find, especially when smoke comes from the exhaust. Smoke that comes from the exhaust can be caused by a defective unit injector, but it can also be caused by one or more of the reasons that follow:

* Not enough air for good combustion.

* An overload at high altitude.

* Oil leakage into combustion chamber.

* Not enough compression.

* Fuel injection timing incorrect.

* Cold engine operation.

* Low octane fuel.

Fuel System Components
(1) Fuel filter base. (2) Fuel line from ECM. (3) Fuel priming pump. (4) Fuel filter. (5) ECM.

Fuel System Components
(6) Fuel supply and return manifold. (7) Fuel transfer pump. (8) Fuel line (fuel transfer pump to ECM).

Fuel System Inspection

A problem with the components that send fuel to the engine can cause low fuel pressure. This can decrease engine performance.

1. Check the fuel level in the fuel tank. Look at the cap for the fuel tank to make sure the vent is not filled with dirt.

2. Check all fuel lines for fuel leakage. Be sure none of the fuel lines have a restriction or a defective bend. Verify that the fuel return line has not collapsed in the sections subject to heat.

3. Install a new fuel filter.

4. Remove any air that may be in the fuel system. Refer to Fuel Priming Procedure in this service manual.

Fuel Transfer Pump

With the engine operating at rated rpm and load condition, the fuel transfer pump moves fuel through the ECM, fuel filter base, and fuel supply and return manifolds. An orificed valve in the return fuel manifold restricts fuel flow. A pressure regulation valve is in the transfer pump. The normal fuel pressure is 630 kPa (91 psi) at rated rpm.

If the fuel pressure is low 517 kPa (75 psi) or less, stop the engine. Replace the fuel filter, and make sure the fuel lines are not plugged or damaged.

Start the engine and again check the fuel pressure. If fuel pressure is still low, check the fuel regulating valve in the fuel transfer pump.

If the fuel pressure is high 690 kPa (100 psi) or above, stop the engine. Remove the orificed valve from the adaptor. The valve is directly behind the return line fitting. Check for debris plugging the orifice holes near the tip. If plugged, flush any remaining debris from the return passage, and check source of debris. If not plugged, check for plugged return fuel line. If no obstructions were found, check the fuel transfer pump regulating valve for debris or rust.

Fuel Pressure

To check the fuel transfer pump pressure, remove the fuel pressure sensor from the fuel filter base. Install a pressure indicator, and start the engine.

The 1U5470 Engine Pressure Group can be used to check engine fuel pressure.

This tool group has a indicator to read fuel pressure to the fuel supply manifold. Special Instruction, SEHS8907 is with the tool group and gives information for its use.

1U5470 Engine Pressure Group

Fuel Priming Procedure

Air Bleed Port Plug
(1) Air bleed port plug. (2) Base assembly.

NOTE: If the fuel system runs out of fuel or air is introduced into the system the following procedure may be followed. This is not necessary when only changing the fuel filter. The engine will remain running after starting with a dry filter.

1. After fuel is added to the fuel tank, remove plug (1) in fuel filter base.

2. Use the hand priming pump to purge air from the fuel system and to pump fuel into the system. Stop pumping when fuel appears at the port.

3. Install plug (1). Continue pumping until a strong pressure is felt on the pump, and you hear a "click" from the fuel filter base. This pressurizes the system with approximately 345 kpa (50 psi) and dramatically reduces engine crank time. When finished, lock the pump in the bottom position to avoid possible damage to the pump.

4. Crank the engine as soon as possible after pressurizing the system. It should start within 15 seconds. If not started after 30 seconds, stop and wait two minutes. Repeat Step 3 to repressurize the system, and crank engine again for up to 30 second.

Unit Injector Adjustment

Injector Mechanism
(1) Rocker arm. (2) Adjusting screw. (3) Locknut.

To make an adjustment to the unit injectors on cylinders 3, 5, and 6 use the following procedure:

1. Put No. 1 piston at top center (TC) on the compression stroke. See the topic, Finding Top Center Position For No. 1 Piston.

2. Turn the unit injector adjusting screw (2) CW (clockwise) until contact is made with the unit injector.

3. Turn the adjusting screw CW (clockwise) an additional 180 degrees (1/2 turn).

4. Hold the adjusting screw in this position and tighten the locknut (3) to a torque of 55 ± 10 N·m (41 ± 7 lb ft).

5. To make an adjustment to the unit injectors on cylinders 1, 2, and 4 remove the timing bolt and turn the flywheel 360 degrees in the direction of engine rotation (counterclockwise). This will put No. 1 piston at top center (TC) on the exhaust stroke.

6. Repeat Steps 2 through 4.

7. Remove the timing bolt from the flywheel when all the unit injector adjustments have been made, and reinstall the timing cover.

Checking Engine Cylinders Separately

Temperature of an exhaust manifold port, when the engine runs at low idle, can be an indication of the condition of a unit injector. Low temperature at an exhaust manifold port is an indication of no fuel to the cylinder. This could be caused by an inoperative unit injector. Extra high temperature at an exhaust manifold port can be an indication of too much fuel to the cylinder, caused by a malfunctioning unit injector.

Use the 123-6700 Infrared Thermometer to check exhaust temperature. The Operator's Manual, NEHS0630, for the 123-6700 Infrared Thermometer gives complete operating and maintenance instructions for this tool.

Static Check Of The Timing Gear Position Used To Reference Electronic Injection Timing/Front Gear Group Alignment

Front Gear Group (with front cover removed)
(1) Camshaft gear/timing reference ring. (2) Timing marks. (3) Idler gear. (4) Crankshaft gear.

The basis for correct fuel injection timing and valve mechanism operation is determined by the timing reference ring and the alignment of the front gear group. The timing reference ring is located on the end of the camshaft group, and it is used to measure crankshaft rotation. During installation of the front gear group, timing marks (2) on idler gear (3) must be in alignment with the timing marks on crankshaft gear (4) and the timing marks on camshaft gear/timing reference ring (1). For a complete removal and installation procedure of the front gear group, see the topic, Front Gear Group, in the Disassembly & Assembly module.

NOTE: It is possible to install the Timing Reference Ring backwards. If this occurs, the engine will not start.

Check for proper alignment of the camshaft gear/timing reference ring (1) on the camshaft assembly. Inspect the key between the timing reference ring and the camshaft gear. Check the timing ring teeth. The teeth should not be defaced, and should have sharp clean edges and be free of contaminants.

NOTE: The electronic injection timing must be calibrated after re-assembly of the front gear train.

Finding Top Center Position For No. 1 Piston

Locating Top Center
(1) Bolts (two-6V5219). (2) Cover. (3) Flywheel housing.

1. Remove two bolts (1) and remove cover (2) from the flywheel housing (3) to open the turning hole.

2. Put one of the 6V5219 Bolts (1) in the timing hole located approximately 127 to 152 mm (5 to 6 in) above the turning hole in the flywheel housing. Use the 9S9082 Engine Turning Tool and a 1/2 inch drive ratchet wrench to turn the engine flywheel in the direction of normal engine rotation (counterclockwise when viewed from the flywheel end) until the timing bolt engages with the threaded hole in the flywheel.

NOTE: If the flywheel is turned beyond the point that the timing bolt engages in the threaded hole, the flywheel must be turned opposite normal engine rotation approximately 30 degrees. Then turn the flywheel in the direction of normal rotation (counterclockwise) until the timing bolt engages with the threaded hole. The reason for this procedure is to make sure the play is removed from the gears when the No. 1 piston is put on top center.

3. Remove the front valve cover from the engine.

4. The inlet and exhaust valves for the No. 1 cylinder are fully closed if No. 1 piston is on the compression stroke and the rocker arms can be moved by hand. If the rocker arms cannot be moved and the valves are slightly open, the No. 1 piston is on the exhaust stroke.

NOTE: When the actual stroke position is identified, and the other stroke position is needed, it is necessary to remove the timing bolt from the flywheel, turn the flywheel counterclockwise 360 degrees, and reinstall the timing bolt.

Electronic Injection Timing Troubleshooting

Electronic injection timing troubleshooting is required if the electronic injection timing is inconsistent or it will not calibrate correctly. If either of these conditions are present, see the topic, Engine Timing Calibration Procedures in the Electronic Troubleshooting, SENR1180.

Engine Speed Measurement

9U7400 Multitach Group

The 9U7400 Multitach Group can measure engine speed from a magnetic pickup on the flywheel housing. It also has the ability to measure engine speed from visual engine parts in rotation.

Operators Manual, NEHS0605 is with the 9U7400 Multitach Group and gives instructions for the test procedure.

Air Inlet And Exhaust System

Restriction Of Air Inlet And Exhaust

There will be a reduction of horsepower and efficiency of the engine if there is a restriction in the air inlet or exhaust system.

Air flow through the air cleaner must not have a restriction (negative pressure difference measurement between atmospheric air and air that has gone through air cleaner) of more than 635 mm (25 inches of H₂O) with a used or plugged air cleaner element. Air flow through the air cleaner must not have a restriction (negative pressure difference measurement between atmospheric air and air that has gone through air cleaner) of more than 381 mm (15 inches of H₂O) with a new air cleaner element.

Back pressure from the exhaust (pressure difference measurement between exhaust at outlet elbow and atmospheric air) must not be more than 1016 mm (40 inches of H₂O).

Measurement Of Pressure In Inlet Manifold

The efficiency of an engine can be checked by making a comparison of the pressure in the inlet manifold with the information given in the TMI (Technical Marketing Information), or Fuel Setting And Related Information Fiche. This test is used when there is a decrease of horsepower from the engine, yet there is no real sign of a problem with the engine.

The correct pressure for the inlet manifold is given in the TMI (Technical Marketing Information), or Fuel Setting And Related Information Fiche. Development of this information is done with these conditions:

a. 99 kPa (29.7 inches of Hg) (DRY) barometric pressure.

b. 29°C (85°F) outside air temperature.

c. 35 API rated fuel.

On a turbocharged and aftercooled engine, a change in fuel rating will also change horsepower and the pressure in the inlet manifold. If the fuel is rated above 35 API, pressure in the inlet manifold can be less than given in the TMI (Technical Marketing Information), or Fuel Setting And Related Information Fiche. If the fuel is rated below 35 API, the pressure in the inlet manifold can be more than given in the TMI (Technical Marketing Information), or Fuel Setting And Related Information Fiche. Be Sure That The Air Inlet Or Exhaust Does Not Have A Restriction When Making A Check Of Pressure In The Inlet Manifold.

Pressure Test Location On Inlet Manifold
(1) Plug.

To measure the inlet manifold pressure, remove plug (1) from the inlet manifold. Use the 1U5470 Engine Pressure Group to check the pressure in the inlet manifold.

1U5470 Engine Pressure Group

This tool group has a indicator to read pressure in the inlet manifold. Special Instruction, SEHS8907 is with the tool group and gives instructions for its use.

Exhaust Temperature

Use the 123-6700 Infrared Thermometer to check exhaust temperature. The Operator's Manual, NEHS0630, for the 123-6700 Infrared Thermometer gives complete operating and maintenance instructions for this tool.

Air-To-Air Aftercooled Systems

Visual Inspection

Inspect all air lines, hoses and gasket connections at each oil change. Make sure the constant torque hose clamps are tightened to the correct torque. Check the vehicle manufacturer's specifications for the correct torque. Check welded joints for cracks and make sure all brackets are tightened in position and are in good condition. Use compressed air to clean cooler core blockage caused by debris or dust. Inspect the cooler core fins for damage, debris or salt corrosion. Use a stainless steel brush with soap and water to remove corrosion.

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Pressure air can cause personal injury. When using pressure air for cleaning, wear a protective face shield, protective clothing and protective shoes.

NOTE: When air-to-air aftercooler system parts are repaired and/or replaced, a leak test is recommended.

The use of winter fronts or shutters is discouraged with air-to-air aftercooled systems. Winter fronts can only be used on vehicle models where tests have shown that the engine jacket water will overheat before the inlet manifold air temperature is excessive. On these vehicles, sensors and indicators or alarms are installed to indicate engine operating conditions before excessive inlet manifold air temperatures are reached. Check with the vehicle manufacturer on winter front and shutter application.

Air System Restriction

Pressure measurements should be taken at the turbocharger outlet and at the inlet manifold. When the total pressure drop of the charged air system at maximum air flow exceeds 13.5 kPa (4 inches of Hg), the air lines and cooler core must be inspected for internal restriction and cleaned, repaired or replaced as necessary.

Turbocharger Failure

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Pressure air can cause personal injury. When using pressure air for cleaning, wear a protective face shield, protective clothing and protective shoes. The maximum air pressure must be below 205 kPa (30 psi) for cleaning purposes.

If a turbocharger failure occurs, remove the air-to-air aftercooler core and flush internally with a solvent that removes oil and other foreign substances. Shake cooler to eliminate any trapped debris. Wash with hot, soapy water; rinse thoroughly with clean water; and blow dry with compressed air in reverse direction of normal air flow. Carefully inspect the system to make sure it is clean.

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NOTICE
Do not use caustic cleaners or damage to the aftercooler core will result.

Inlet Manifold Pressure

Normal inlet manifold pressure with high exhaust temperature can be caused by cooler core fin blockage. Clean the cooler core fins, see Visual Inspection for the cleaning procedure to use.

Low inlet manifold pressure and high exhaust manifold temperature can be caused by any of the conditions that follow:

1. A plugged air cleaner. Clean or replace the air cleaner as needed.

2. A blockage in the air lines between the air cleaner and turbocharger. All restrictions must be removed.

3. Cooler core leakage. Pressure test the cooler core, see Aftercooler Core Leakage for the correct procedure to use and repair or replace parts as needed.

4. Leakage from the pressure side of the induction system. Check and repair leaks.

5. Inlet manifold leak. Check for loose, missing and damaged fittings or plugs. Also check the manifold to cylinder head gaskets.

Aftercooler Core Leakage

FT1984 Air-To-Air Aftercooler Test Group
(1) Regulator and valve assembly. (2) Nipple. (3) Relief valve. (4) Tee. (5) Couplers. (6) Aftercooler. (7) Dust plug. (8) Dust plug. (9) Chain.

A low power problem in the engine can be the result of aftercooler leakage. Low power, low boost pressure, black smoke, and/or high exhaust temperature can be the result of an aftercooler system leakage.

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NOTICE
Remove all air leaks from the system to prevent engine damage. In some operating conditions, the engine can pull a manifold vacuum for short periods of time. A leak in the aftercooler or air lines can let dirt and other foreign material into the engine and cause rapid wear and/or damage to engine parts.

A large cooler core leak often can be found by making a visual inspection. To check for smaller leaks, use the following procedure:

1. Disconnect the air pipes from the inlet and outlet side of the aftercooler core.

2. Install couplers (5) and dust plugs (7) and (8) from the FT1984 Air-To-Air Aftercooler Test Group as shown on each side of the aftercooler core. Installation of additional hose clamps on hump hoses is recommended to prevent the hoses from bulging while the aftercooler core is being pressurized.

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Dust plug chains (9) must be installed to the aftercooler core or the radiator brackets to prevent possible injury while testing. Do not stand in front of the dust plugs while testing.

3. Install regulator and valve assembly (1) on the outlet side of the aftercooler. Attach air supply.

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NOTICE
Do not use more than 240 kPa (35 psi) air pressure or damage to the aftercooler core can be the result.

4. Open air valve and pressurize the aftercooler to 205 kPa (30 psi). Shut off air supply.

5. Inspect all connections for air leakage.

6. System pressure should not drop more than 35 kPa (5 psi) in 15 seconds.

7. If the pressure drop is more than specified, use a solution of soap and water to check all areas of possible leakage and look for air bubbles. Replace hoses or repair the aftercooler core as needed.

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To help prevent personal injury when the tooling is removed, relieve all pressure in the system slowly by using air regulator and valve assembly (5).

8. After testing, remove FT Tooling and connect air pipes on each side of the aftercooler.

Dynamometer Test

Air-to-air aftercooled chassis dynamometer tests, in hot ambient temperatures, can add a greater heat load to the jacket water cooling system, therefore the jacket water cooling system temperature must be monitored. Also, monitor the inlet air temperature as it may need a power correction factor along with fuel API, fuel temperature and barometric pressure.

For engine dynamometer tests, use the FT1438 Dynamometer Testing Aftercooler. FT1438 provides an air to water aftercooler to control the inlet air temperature to 43°C (110°F).

Crankcase (Crankshaft Compartment) Pressure

Pistons or rings that have damage can be the cause of too much pressure in the crankcase. This condition will cause the engine to run rough. There will also be more than the normal amount of fumes (blowby) coming from the crankcase breather. The breather can then become restricted in a very short time, causing oil leakage at gaskets and seals that would not normally have leakage. Other sources of blowby can be worn valve guides or turbocharger seal leakage.

8T2700 Indicator Group

The 8T2700 Indicator Group is used to check the amount of blowby. The test procedure is in Special Instruction, SEHS8712.

Compression

An engine that runs rough can have a leak at the valves, or have valves that need adjustment. Removal of the head and inspection of the valves and valve seats is necessary to find those small defects that do not normally cause a problem. Repair of these problems is normally done when reconditioning the engine.

Cylinder Head

The cylinder head has valve seat inserts, valve guides and valve bridge dowels that can be removed when they are worn or have damage. Replacement of these components can be made with the tools that follow. Most of the tools are part of the 1U9654 Head Repair Tool Group.

NOTE: The Disassembly & Assembly module contains a complete procedure for removing and installing the cylinder head components.

Valves

For valve removal and installation use the 5S1330 Valve Spring Compressor Assembly or 4C6726 Valve Spring Compressor Group, and the 5S1332 Valve Keeper Inserter.

NOTE: A 1U7798 Hammer and 1U7794 Shaft Assembly are used to remove and install the valve seat inserts and valve guides.

Valve Seat Inserts

Tools needed to remove and install the valve seat inserts are: 1U9166 Valve Seat Extractor for inlet valves, 1U9167 Valve Seat Extractor for exhaust valves, 1U9170 Valve Seat Driver, and 1U9706 Plate (for exhaust seats).

Valve Guides

Tools needed to remove and install the valve guides are the 1U9168 Valve Guide Collar (Stop) and the 1U9169 Valve Guide Driver.

Checking Valve Guide Bores

Use the 5P3536 Valve Guide Gauge Group to check the bore of the valve guides. Special Instruction, GMG02562 gives complete and detailed instructions for use of the 5P3536 Valve Guide Gauge Group.

Valve Lash Setting

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To prevent possible injury, do not use the starting motor to turn the flywheel. Hot engine components can cause burns. Allow additional time for the engine to cool before measuring valve lash. The 3176C and 3196 uses high voltage to the unit injectors. Do not come in contact with the injector terminals while the engine is running. Disconnect J5/P5.

NOTE: Valve lash is measured between the rocker arm and the valve bridge for the valves.

NOTE: When the valve lash is checked, adjustment is Not Necessary if the measurement is in the range given in the chart for Valve Lash Check: Engine Stopped. If the measurement is outside this range, adjustment is necessary. See the chart for Valve Lash Setting: Engine Stopped, and make the setting to the nominal (desired) specifications in this chart.

Cylinder And Valve Location

To make an adjustment to the valve lash, turn the adjustment screw in the rocker arm. Valve lash adjustments can be made by using the procedure that follows:

1. Make an adjustment to the valve lash on the inlet valve for cylinders 1,2, and 4. Make an adjustment to the valve lash on the exhaust valves for cylinders 1,3, and 5.

2. Put No. 1 piston at top center (TC) on the compression stroke. See the topic, Finding Top Center Position For No. 1 Piston.

Inlet Valve Adjustment
(1) Inlet rocker arm. (2) Adjustment locknut.

Exhaust Valve Adjustment
(3) Exhaust rocker arm. (4) Adjustment locknut.

3. After each adjustment, tighten the nut for valve adjustment screw to a torque of 25 ± 7 N·m (18 ± 5 lb ft), and check the adjustment again.

4. Remove the timing bolt and turn the flywheel 360 degrees in the direction of engine rotation. This will put No.6 piston at top center (TC) on the compression stroke. Install the timing bolt in the flywheel.

5. Make an adjustment to the valve lash on the inlet valves for cylinders 3, 5, and 6. Make an adjustment to the valve lash on the exhaust valves for cylinders 2, 4, and 6.

6. After each adjustment, tighten the nut for valve adjustment screw to a torque of 25 ± 7 N·m (18 ± 5 lb ft), and check the adjustment again.

7. Remove the timing bolt from the flywheel when all adjustments to the valve lash have been made, and reinstall the timing cover.

Lubrication System

One of the problems in the list that follows will generally be an indication of a problem in the lubrication system for the engine.

* Too Much Oil Consumption

* Oil Pressure Is Low

* Oil Pressure Is High

* Too Much Bearing Wear

* Increased Oil Temperature

Too Much Oil Consumption

Oil Leakage On Outside Of Engine

Check for leakage at the seals at each end of the crankshaft. Look for leakage at the oil pan gasket and all lubrication system connections. Check to see if oil comes out of the crankcase breather. This can be caused by combustion gas leakage around the pistons. A dirty crankcase breather will cause high pressure in the crankcase, and this will cause gasket and seal leakage.

Oil Leakage Into Combustion Area Of Cylinders

Oil leakage into the combustion area of the cylinders can be the cause of blue smoke. There are four possible ways for oil leakage into the combustion area of the cylinders:

1. Oil leakage between worn valve guides and valve stems.

2. Worn or damaged piston rings, or dirty oil return holes.

3. Compression ring and/or intermediate ring not installed correctly.

4. Oil leakage past the seal rings in the impeller end of the turbocharger shaft.

Too much oil consumption can also be the result if oil with the wrong viscosity is used. Oil with a thin viscosity can be caused by fuel leakage into the crankcase, or by increased engine temperature.

Measuring Engine Oil Pressure

An oil pressure indicator that has a defect can give an indication of low or high oil pressure.

1U5470 Engine Pressure Group

The 1U5470 Engine Pressure Group can be used to measure the pressure in the system independent of the engines electronic sensors. This tool group has a indicator to read pressure in the oil manifold. Special Instruction, SEHS8907 is with the tool group and gives instructions for its use.

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Work carefully around an engine that is running. Engine parts that are hot, or parts that are moving, can cause personal injury.

Engine-Right Side
(1) Plugs.

Oil pressure to the camshaft and main bearings should be checked on the side of the cylinder block at oil gallery plugs (1). Install the 1U5470 Engine Pressure Group into this opening. With the engine at operating temperature (using SAE 15W40 oil), under full load condition, oil pressure should be 275 to 414 kPa (40 to 60 psi). With the engine at operating temperature (using SAE 15W40 oil), at 600 to 800 rpm low idle, minimum oil pressure is 68 kPa (10 psi).

Oil Pressure Is Low

Crankcase Oil Level

Check the level of the oil in the crankcase. Add oil if needed. It is possible for the oil level to be too far below the engine oil pump supply tube. This will cause the engine oil pump not to have the ability to supply enough lubrication to the engine components.

Engine Oil Pump Does Not Work Correctly

The inlet screen of the supply tube for the engine oil pump can have a restriction. This will cause cavitation (low pressure bubbles suddenly made in liquids by mechanical forces) and a loss of oil pressure. Air leakage in the supply side of the engine oil pump will also cause cavitation and loss of oil pressure. If the bypass valve for the engine oil pump is held in the open (unseated) position, the lubrication system cannot get to maximum pressure. Oil pump gears that have too much wear will cause a reduction in oil pressure.

Oil Filter Bypass Valve

If the bypass valve for the engine oil filter is held in the open position (unseated) because the engine oil filter has a restriction, a reduction in oil pressure can result. To correct this problem, remove and clean the bypass valve and bypass valve bore. Install a new engine oil filter to be sure that no more debris makes the bypass valve stay open.

Too Much Clearance At Engine Bearings Or Open Lubrication System (Broken Or Disconnected Oil Line Or Passage)

Components that are worn and have too much bearing clearance can cause oil pressure to be low. Low oil pressure can also be caused by an oil line or oil passage that is open, broken or disconnected.

Piston Cooling Jets

When engine is operated, piston cooling jets direct oil toward the bottom of the piston to cool the piston and also provide lubrication for the piston pin. If a piston cooling jet is broken, plugged or installed incorrectly, seizure of the piston may result in a very short time.

Oil Pressure Is High

Oil pressure will be high if the bypass valve for the engine oil pump cannot move from the closed position.

Too Much Bearing Wear

When some components of the engine show bearing wear in a short time, the cause can be a restriction in an oil passage.

If the indicator for oil pressure shows enough oil pressure, but a component is worn because it cannot get enough lubrication, look at the passage for oil supply to the component. A restriction in a supply passage will not let enough lubrication get to a component, and this will cause early wear.

Increased Oil Temperature

With the engine at operating temperature (using SAE 15W40 oil), the maximum oil temperature is 110°C (230°F). This temperature is from or after the engine oil cooler.

Look for a restriction in the oil passages of the engine oil cooler. If the engine oil cooler has a restriction, the oil temperature will be higher than normal when the engine is operated. The oil pressure of the engine will not get low just because the engine oil cooler has a restriction.

Also check the oil cooler bypass valve to see if it is held in the open position (unseated). This condition will let the oil through the valve instead of the engine oil cooler, and oil temperature will increase.

Indicators For Oil Pressure

An oil pressure indicator or a sender that has a defect can give an indication of low or high oil pressure.

The 1U5470 Engine Pressure Group can be used to make a comparison with instrument panel indicators.

Cooling System

This engine has a pressure type cooling system. A pressure type cooling system gives two advantages. The first advantage is that the cooling system can have safe operation at a temperature that is higher than the normal boiling (steam) point of water. The second advantage is that this type system prevents cavitation (low pressure bubbles suddenly made in liquids by mechanical forces) in the water pump. With this type system, it is more difficult for an air or steam pocket to be made in the cooling system.

The cause for increased engine temperature is generally because regular inspections of the cooling system were not made. Make a visual inspection of the cooling system before a test is made with test equipment.

Visual Inspection Of The Cooling System

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

NOTE: Water pump seals. A small amount of coolant leakage across the surface of the "face-type" seals is normal, and required, to provide lubrication for this type of seal. A hole is provided in the water pump housing to allow this coolant/seal lubricant to drain from the pump housing. Intermittent leakage of small amounts of coolant from this hole is not an indication of water pump seal failure. Replace the water pump seals only if a large amount of leakage, or a constant flow of coolant is observed draining from the water pump housing. See the topic, Water Pump, Disassemble & Assemble, for a complete description of replacement of the water pump seals.

3. Look for bent radiator fins. Be sure that air flow through the radiator does not have a restriction.

4. Inspect the drive belt for the fan.

5. Check for damage to the fan blades.

6. Look for air or combustion gas in the cooling system.

7. Inspect the filler cap and the surface that seals the cap. This surface must be clean.

Testing The Cooling System

Remember that temperature and pressure work together. When a diagnosis is made of a cooling system problem, temperature and pressure must both be checked. Cooling system pressure will have an effect on cooling system temperatures. For an example, look at the chart to see the effect of pressure and height above sea level on the boiling (steam) point of water.

To check the cooling system, the coolant level must be to the correct level with the engine stopped and cold.

After the engine is cool, loosen the pressure cap and let the pressure out of the cooling system. Then remove the pressure cap.

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DO NOT loosen the filler or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

The level of the coolant should be within 13 mm (1/2 in) below the bottom of the fill pipe or to the proper level on the sight glass, if so equipped.

Test Tools For Cooling System

4C6500 Digital Thermometer Group

The 4C6500 Digital Thermometer Group is used in the diagnosis of over heating (engine hotter than normal) or overcooling (engine cooler than normal) problems. This group can be used to check temperatures in several different parts of the cooling system. The testing procedure is in Special Instruction, NEHS0554.

8T2700 Indicator Group

The 8T2700 Blowby/Air Flow Indicator Group is used to check the air flow through the radiator core. The test procedure is in Special Instruction, SEHS8712.

9U7400 Multitach Group

The 9U7400 Multitach Group is used to check the fan speed. The testing procedure is in Operators Instruction, SEHS0605.

1U7297 or 1U7298 Coolant Tester

Check the coolant solution frequently in cold weather for glycol concentration with the 1U7297 or 1U7298 Coolant Tester to ensure adequate protection. Both testers are used for checking coolant freezing point, and are identical except temperature scale. They give immediate, accurate readings and can be used for antifreeze/coolants that contain ethylene or propylene glycol.

Make Proper Antifreeze Additions

Adding pure antifreeze as a makeup solution for cooling system top-off is an unacceptable practice. It increases the concentration of antifreeze in the cooling system which increases the concentration of dissolved solids and undissolved chemical inhibitors in the cooling system. Add antifreeze mixed with acceptable water to the same freeze protection as your cooling system. Use the chart as follows to assist in determining the concentration of antifreeze to use.

Checking Pressure Cap

One cause for a pressure loss in the cooling system can be a defective seal on the radiator pressure cap.

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DO NOT loosen the filler or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

After the engine is cool, loosen the pressure cap and let the pressure out of the cooling system. Then remove the pressure cap.

Inspect the pressure cap carefully. Look for damage to the seal or to the surface that seals. Any foreign material or deposits on the cap, seal or surface that seals, must be removed.

Typical Schematic Of Pressure Cap
(A) Sealing surface of cap and radiator.

9S8140 Cooling System Pressurizing Pump Group

The 9S8140 Cooling System Pressurizing Pump Group is used to test pressure caps and to pressure check the cooling system for leaks.

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DO NOT loosen the filler or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

To check the pressure cap for the pressure that makes the pressure cap open, use the procedure that follows:

1. Remove the pressure cap from the radiator.

2. Put the pressure cap on the 9S8140 Cooling System Pressurizing Pump Group.

3. Look at the indicator for the exact pressure that makes the pressure cap open.

4. Make a comparison of the reading on the indicator with the correct pressure at which the pressure cap must open.

5. If the pressure cap is defective, install a new pressure cap.

Testing Radiator And Cooling System For Leaks

To test the radiator and cooling system for leaks, use the procedure that follows:

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DO NOT loosen the filler or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

1. Remove the pressure cap from the radiator.

2. Make sure the coolant is over the top of the radiator core.

3. Put the 9S8140 Cooling System Pressurizing Pump Group on the radiator.

4. Get the pressure reading on the indicator to 20 kPa (3 psi) more than the pressure on the pressure cap.

5. Check the radiator for outside leakage.

6. Check all connections and hoses for the cooling system for outside leakage.

7. If you do not see any outside leakage and the pressure reading on the indicator is still the same after five minutes, the radiator and cooling system does not have leakage. If the reading on the indicator goes down and you do not see any leakage, there is leakage on the inside of the cooling system. Make repairs as necessary.

Water Temperature Indicator Test

Test Location
(1) Plugs.

Check the accuracy of the water temperature indicator if either of the conditions that follow are found:

1. The indicator reads normal, but the engine is too hot and a loss of coolant is found.

2. The indicator shows that the engine is hot, but no loss of coolant can be found.

Remove either of two plugs (1) and install the 4C6500 Digital Thermometer Group or the 2F7112 Thermometer. A temperature indicator of known accuracy can also be used to make this check.

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Work carefully around an engine that is running. Engine parts that are hot, or parts that are moving, can cause personal injury.

Start the engine and run it until the temperature reaches the desired range according to the test thermometer. If necessary, put a cover over part of the radiator or cause a restriction of the air flow. The reading on the indicator for water temperature should agree with test thermometer within the tolerance range of the indicator.

Water Temperature Regulator Test

1. Remove the water temperature regulator from the engine.

2. Heat water in a pan until the temperature is 98°C (208°F). Move the water around in the pan to make it all the same temperature.

3. Hang the water temperature regulator in the pan of water. The water temperature regulator must be below the surface of the water and it must be away from the sides and bottom of the pan.

4. Keep the water at the correct temperature for ten minutes.

5. After ten minutes, remove the water temperature regulator and immediately measure the distance the water temperature regulator has opened. The distance must be a minimum of 10.4 mm (.41 in).

6. If the distance is less than 10.4 mm (.41 in), make a replacement of the water temperature regulator.

Water Pump Pressure Check

(1) Plug. (2) Coolant temperature sensor. (3) Water manifold assembly. (4) Water outlet. (5) Temperature regulator housing. (6) Bypass line. (7) Water pump. (8) Plug.

Water pump outlet pressure can be checked on water manifold assembly (3) next to the coolant temperature sensor (2). This check will determine if the water pump is operating correctly.

Remove plug (1) from water manifold assembly (3). Install the pressure indicator (6V7775) in the port and measure the pump pressure. The water pump pressure should be 100 to 125 kPa (15 to 18 psi).

A change in pressure can be measured between plug (1) on the water manifold assembly (4) and plug (8) on the inlet side of water pump (7).

Basic Block

Piston Rings

This engine has a top piston groove and ring of the keystone (taper) design. The 1U6431 Keystone Piston Ring Groove Gauge Group is available to check the top ring groove in the piston. Use the 8T3149 (#F) Gauge Assembly that is part of this Gauge Group to check the top ring groove on the piston. Refer to the instruction card for correct use of the 1U6431 Gauge Group.

Connecting Rods And Pistons

The 3176C engine uses a 1U9593 Cylinder Pack Removal Group and the 3196 engine uses a 129-6675 Cylinder Pack Removal Group with a 1U9897 Bridge, and a 1U6319 Socket to remove a cylinder pack (connecting rod and piston) from the block. Use the 1U9788 Nylon Brush, or the 1U9787 Flex (hone) for reconditioning of the cylinder liners.

Use the 4C3601 Piston Ring Expander to remove or install piston rings.

Use the 1U6684 Piston Ring Compressor to install pistons into cylinder block.

Tighten the connecting rod nuts in the step sequence that follows:

1. Put 2P2506 Thread Lubricant on bolt threads and contact surfaces of nut and cap.

2. Install connecting rod nuts as follows:

Tighten 3176C connecting rod nuts to a torque of ... 130 ± 7 N·m (95 ± 5 lb ft).

Tighten 3196 connecting rod nuts to a torque of ... 110 ± 7 N·m (80 ± 5 lb ft)

3. Put a mark on each nut and end of bolt.

4. Tighten each nut an additional 60 ± 5 degrees (1/6turn).

The connecting rod bearings fit tightly in the bore in the rod. If bearing joints or backs are worn (fretted), check bore size. This can be an indication of wear because of a loose fit.

Connecting Rod And Main Bearings

Connecting Rod Bearings

Connecting rod bearings are available with 0.508 mm (.0200 in) and .762 mm (.0300 in) smaller inside diameter than the original size bearings. These bearings are for crankshafts that have been "ground" (made smaller than the original size).

Main Bearings

Main bearings are available with 0.508 mm (.0200 in) and .762 mm (.0300 in) smaller inside diameter than the original size bearings. These bearings are for crankshafts that have been "ground" (made smaller than the original size).

Main bearings are also available with a larger outside diameter than the original size bearings. These bearings are for cylinder blocks that have had the bore for the main bearings "bored" (made larger than the original size). The size available is 0.508 mm (.0200 in) larger outside diameter than the original size bearings.

Cylinder Block

1P3537 Dial Bore Gauge Group

The bore in the block for main bearings can be checked with the main bearing caps installed without bearings. Tighten the nuts that hold the caps to the torque shown in the Specifications. Alignment error in the bores must not be more than 0.08 mm (.003 in).

Special Instruction, SMHS7606 gives instructions for the use of 1P4000 Line Boring Tool Group for alignment of the main bearing bores. The 1P3537 Dial Bore Gauge Group can be used to check the size of the bores. Special Instruction, GMG00981 is with the group.

Cylinder Liner Projection

1. Clean the cylinder liner flange and cylinder block surface. Remove any nicks on the top of the cylinder block.

Location Of Components Required To Retain The Cylinder Liner When Measuring Cylinder Liner Projection
(1) 8T4193 Bolt. (2) 2S5658 Washer. (3) 8F1484 Washer. (4) Washer.

2. The illustration and chart identify the components required. An 8T0455 Cylinder Liner Projection Indicator Group is also required.

3. Assemble the components as shown in the illustration. The 7K1977 Washer (4) is made of a cotton fabric that is impregnated with resin. It will not damage the sealing surface of the cylinder block.

NOTE: Inspect washer before measuring liner projection and replace if worn or damaged.

4. Tighten bolts (1) evenly as follows:

a. First tighten each bolt to ... 27 N·m (20 lb ft)

b. Tighten each bolt to ... 54 N·m (40 lb ft)

c. Tighten each bolt to ... 68 N·m (50 lb ft)

d. Tighten each bolt again to ... 68 N·m (50 lb ft)

Liner Projection Tool
(5) 5S2671 Bolt. (6) 1P2403 Dial Indicator. (7) 1P2402 Gauge Body. (8) 1P5507 Gauge.

5. Loosen 5S2671 Bolt (5) until 1P2403 Dial Indicator (6) can be moved. Place 1P2402 Gauge Body (7) and 1P2403 Dial Indicator (6) on the long side of gauge.

6. Slide 1P2403 Dial Indicator (6) down until the point contacts gauge (8) and moves the needle 1/4revolution clockwise to a vertical position. Tighten 1P2402 Bolt (5) and zero 1P2403 Dial Indicator (6).

Liner Projection Tool
(5) 5S2671 Bolt. (6) 1P2403 Dial Indicator. (8) 1P5507 Gauge.

7. Put 1P2402 Gauge Body (7) on the cylinder block plate, with the indicator point on the liner flange. Read the 1P2403 Dial Indicator (6) to find the amount of liner projection. Check projection at four locations (90 degrees apart) around each cylinder liner.

8. If a liner does not meet the liner projection specifications, check the block cylinder bore depth 100.00 ± 0.03 mm (3.937 ± .001 in) and the liner flange 100.12 ± 0.03 mm (3.942 ± 0.001 in) to determine if they are correct. If not within specification, replace and repeat the liner projection measurements.

Flywheel And Flywheel Housing

Face Run Out (Axial Eccentricity) Of The Flywheel Housing

8T5096 Dial Indicator Group Installed (Typical Example)

If any method other than given here is used, always remember bearing clearance must be removed to get correct measurements.

1. Fasten a dial indicator to the flywheel so the anvil of the indicator will touch the face of the flywheel housing.

2. Put a force on the crankshaft toward the rear before the indicator is read at each point.

Checking Face Runout Of The Flywheel Housing

3. With dial indicator set at "0" (zero) at location (A), turn the flywheel and read the indicator at locations (B), (C) and (D).

4. The difference between lower and higher measurements taken at all four points must not be more than 0.38 mm (.015 in), which is the maximum permissible face run out (axial eccentricity) of the flywheel housing.

Bore Runout (Radial Eccentricity) Of The Flywheel Housing

1. Fasten the dial indicator as shown so the anvil of the indicator will touch the bore of the flywheel housing.

2. With the dial indicator in position at (C), adjust the dial indicator to "0" (zero). Push the crankshaft up against the top of the bearing. Write the measurement for bearing clearance on line 1 in column (C) in the Chart For Dial Indicator Measurements.

8T5096 Dial Indicator Group Installed (Typical Example)

NOTE: Write the dial indicator measurements with their positive (+) and negative (-) notation (signs). This notation is necessary for making the calculations in the chart correctly.

3. Divide the measurement from Step 2 by 2. Write this number on line 1 in columns (B) & (D).

4. Turn the flywheel to put the dial indicator at (A). Adjust the dial indicator to "0" (zero).

5. Turn the flywheel counterclockwise to put the dial indicator at (B). Write the measurements in the chart.

Checking Bore Runout Of The Flywheel Housing

6. Turn the flywheel counterclockwise to put the dial indicator at (C). Write the measurement in the chart.

7. Turn the flywheel counterclockwise to put the dial indicator at (D). Write the measurement in the chart.

8. Add lines I & II by columns.

9. Subtract the smaller number from the larger number in line III in columns (B) & (D). The result is the horizontal eccentricity (out of round). Line III, column (C) is the vertical eccentricity.

10. On the graph for total eccentricity, find the point of intersection of the lines for vertical eccentricity and horizontal eccentricity.

11. If the point of intersection is in the range marked "Acceptable", the bore is in alignment. If the point of intersection is in the range marked "Not Acceptable", the flywheel housing must be changed.

Graph For Total Eccentricity
(1) Total Vertical Eccentricity [mm (in)]. (2) Total Horizontal Eccentricity [mm (in)]. (3) Acceptable. (4) Not Acceptable.

Face Runout (Axial Eccentricity) Of The Flywheel

1. Install the dial indicator as shown. Always put a force on the crankshaft in the same direction before the indicator is read so the crankshaft end clearance (movement) is always removed.

Checking Face Runout Of The Flywheel (Typical Example)

2. Set the dial indicator to read "0" (zero).

3. Turn the flywheel and read the indicator every 90 degrees.

4. The difference between the lower and higher measurements taken at all four points must not be more than 0.15 mm (.006 in), which is the maximum permissible face runout (axial eccentricity) of the flywheel.

Bore Runout (Radial Eccentricity) Of The Flywheel

Checking Bore Runout Of The Flywheel (Typical Example)
(1) 7H1945 Holding Rod (2) 7H1645 Holding Rod (3) 7H1942 Indicator (4) 7H1940 Universal Attachment

1. Install the dial indicator (3) and make an adjustment of the universal attachment (4) so it makes contact as shown.

2. Set the dial indicator to read "0" (zero).

3. Turn the flywheel and read the indicator every 90 degrees.

4. The difference between the lower and higher measurements taken at all four points must not be more than 0.15 mm (.006 in), which is the maximum permissible bore runout (radial eccentricity) of the flywheel.

5. Runout (eccentricity) of the bore for the pilot bearing for the flywheel clutch, must not exceed 0.13 mm (.005 in).

Checking Flywheel Clutch Pilot Bearing Bore

Vibration Damper

(1) Vibration damper. (2) Pulley. (3) Crankshaft. (4) Bolts.

The vibration damper is installed on the front of crankshaft (3). The vibration damper (1) has a weight in a case. The space between the weight and the case is filled with thick fluid. The weight moves in the case to limit the torsional vibration.

If the damper is leaking, bent or damaged, or if the bolt holes in the damper are loose fitting, replace the damper. Replacement of the damper is also needed at the time of a crankshaft failure due to torsional forces.

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NOTICE
Inspect the viscous damper for signs of leakage or a dented (damaged) case. Either condition can cause the weight to make contact with the case and affect damper operation.

NOTE: Bolts (4) must be tightened to a torque of 240 ± 40 N·m (175 ± 30 lb ft).

Electrical System

Test Tools For Electrical System

Most of the tests of the electrical system can be done on the engine. The wiring insulation must be in good condition, the wire and cable connections must be clean and tight, and the battery must be fully charged. If the on-engine test shows a defect in a component, remove the component for more testing.

The service manual Testing & Adjusting Electrical Components, REG00636 has complete specifications and procedures for the components of the starting circuit and the charging circuit.

4C4911 Battery Load Tester

The 4C4911 Battery Load Tester is a portable unit in a metal case for use under field conditions and high temperatures. It can be used to load test all 6, 8 and I2V batteries. This tester has two heavy-duty load cables that can easily be fastened to the battery terminals. A load adjustment knob on the top permits the current being drawn from the battery to be adjusted to a maximum of 1000 amperes. The tester is cooled by an internal fan that is automatically activated when a load is applied.

The tester has a built in LCD digital voltmeter and amperage meter. The digital voltmeter accurately measures the battery voltage at the battery through tracer wires buried inside the load cables. The digital amperage meter accurately displays the current being drawn from the battery under test.

NOTE: Make reference to Operating Manual, SEHS9249 for more complete information for use of the 4C4911 Battery Load Tester.

8T0900 AC/DC Clamp-On Ammeter

The 8T0900 AC/DC Clamp-On Ammeter is a completely portable, self-contained instrument that allows electrical current measurements to be made without breaking the circuit or disturbing the insulation on conductors. A digital display is located on the ammeter for reading current directly in a range from 1 to 1200 amperes. If an optional 6V6014 Cable is connected between this ammeter and one of the digital multimeters, current readings of less than 1 ampere can then be read directly from the display of the multimeter.

A lever is used to open the jaws over the conductor [up to a diameter of 19 mm (.75 in)], and the spring loaded jaws are then closed around the conductor for current measurement. A trigger switch that can be locked in the ON or OFF position is used to turn on the ammeter. When the turn-on trigger is released, the last current reading is held on the display for five seconds. This allows accurate measurements to be taken in limited access areas where the digital display is not visible to the operator. A zero control is provided for DC operation, and power for the ammeter is supplied by batteries located inside the handle.

NOTE: Make reference to Special Instruction, SEHS8420 for more complete information for use of the 8T0900 Clamp-On Ammeter.

6V7070 Heavy-Duty Digital Multimeter

The 6V7070 Heavy-Duty Digital Multimeter is a completely portable, hand held instrument with a digital display. This multimeter is built with extra protection against damage in field applications, and is equipped with seven functions and 29 ranges. The 6V7070 Multimeter has an instant ohms indicator that permits continuity checking for fast circuit inspection. It also can be used for troubleshooting small value capacitors.

NOTE: Make reference to Special Instruction, SEHS7734 for complete information for use of the 6V7070 Multimeter.

Battery

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Never disconnect any charging unit circuit or battery circuit cable from the battery when the charging unit is operated. A spark can cause an explosion from the flammable vapor mixture of hydrogen and oxygen that is released from the electrolyte through the battery outlets. Injury to personnel can be the result.

The battery circuit is an electrical load on the charging unit. The load is variable because of the condition of the charge in the battery. Damage to the charging unit will result if the connections (either positive or negative) between the battery and charging unit are broken while the charging unit is in operation. This is because the battery load is lost and there is an increase in charging voltage. High voltage will damage, not only the charging unit, but also the regulator and other electrical components.

Use the 4C4911 Battery Load Tester to load test a battery that does not hold a charge when in use. Refer to Operating Manual, SEHS9249 for more detailed instructions on use of the 4C4911 Battery Load Tester. See Special Instruction, SEHS7633, Battery Test Procedure, for the correct procedure and specifications to use when testing batteries.

Charging System

The condition of charge in the battery at each regular inspection will show if the charging system operates correctly. An adjustment is necessary when the battery is constantly in a low condition of charge or a large amount of water is needed (more than one ounce of water per cell per week or per every 100 service hours).

When it is possible, make a test of the charging unit and voltage regulator on the engine, and use wiring and components that are a permanent part of the system. Off-engine (bench) testing will give a test of the charging unit and voltage regulator operation. This testing will give an indication of needed repair. After repairs are made, again make a test to give proof that the units are repaired to their original condition of operation.

To check for correct output of the alternator, see the Specifications module.

For complete service information, refer to Service Manual Module, SENR3862. This module is part of REG00636 Service Manual.

Before the start of on-engine testing, the charging system and battery must be checked as shown in the Steps that follow:

1. Battery must be at least 75 percent (1.225 Sp.Gr.) fully charged and held tightly in place. The battery holder must not put too much stress on the battery.

2. Cables between the battery, starting motor and engine ground must be the correct size. Wires and cables must be free of corrosion and have cable support clamps to prevent stress on battery connections (terminals).

3. Leads, junctions, switches, and panel instruments that have direct relation to the charging circuit must give correct circuit control.

4. Inspect the drive components for the charging unit to be sure they are free of grease and oil and have the ability to operate the charging unit.

Alternator Regulator Adjustment

When an alternator is charging the battery too much or not enough, the charging rate of the alternator should be checked. Make reference to the Specifications module to find all testing specifications for the alternators and regulators.

Alternator
(1) Ground terminal. (2) Pulley nut.

No adjustment can be made to change the rate of charge on the alternator regulators. If rate of charge is not correct, a replacement of the regulator is necessary.

Alternator Pulley Nut Tightening

Tools To Tighten Alternator Pulley Nut
(1) 8T9293 Torque Wrench. (2) 8S1588 Adapter (1/2 inch female to 3/8 inch male). (3) 2P8267 Socket Assembly. (4) 8H8517 Combination Wrench (11/8 inch). (5) 8T5314 Socket.

Tighten nut that holds the pulley to a torque of 102 ± 7 N·m (75 ± 5 lb ft) with the tools shown.

Starting System

Use the multimeter in the DCV range to find starting system components which do not function.

Move the start control switch to activate the starter solenoid. Starter solenoid operation can be heard as the pinion of the starting motor is engaged with the ring gear on the engine flywheel.

If the solenoid for the starting motor will not operate, it is possible that the current from the battery did not get to the solenoid. Fasten one lead of the multimeter to the connection (terminal) for the battery cable on the solenoid. Put the other lead to a good ground. A zero reading is an indication that there is a broken circuit from the battery. More testing is necessary when there is a voltage reading on the multimeter.

The solenoid operation also closes the electric circuit to the motor. Connect one lead of the multimeter to the solenoid connection (terminal) that is fastened to the motor. Put the other lead to a good ground. Activate the starter solenoid and look at the multimeter. A reading of battery voltage shows the problem is in the motor. The motor must be removed for further testing. A zero reading on the multimeter shows that the solenoid contacts do not close. This is an indication of the need for repair to the solenoid or an adjustment to be made to the starter pinion clearance.

Make a test with one multimeter lead fastened to the connection (terminal) for the small wire at the solenoid and the other lead to the ground. Look at the multimeter and activate the starter solenoid. A voltage reading shows that the problem is in the solenoid. A zero reading is an indication that the problem is in the start switch or the wires for the start switch.

Fasten one multimeter lead to the start switch at the connection (terminal) for the wire from the battery. Fasten the other lead to a good ground. A zero reading indicates a broken circuit from the battery. Make a check of the circuit breaker and wiring. If there is a voltage reading, the problem is in the start switch or in the wires for the start switch.

A starting motor that operates too slow can have an overload because of too much friction in the engine being started. Slow operation of the starting motor can also be caused by a short circuit, loose connections and/or dirt in the motor.

To check for correct output of starting motors and starter solenoid, see the Specifications module.

For complete service information, refer to Service Manual Module, SENR3581. This module is part of REG00636 Service Manual.

Pinion Clearance Adjustment

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment can be made with the starting motor removed.

Typical Connection for Checking Pinion Clearance
(1) Connector (from MOTOR terminal on solenoid to motor). (2) Terminal SW. (3) Ground terminal.

1. With the solenoid installed on the starting motor, remove connector (1).

2. Connect a battery, of the same voltage as the solenoid, to the terminal SW (2).

3. Connect the other side of the battery to ground terminal (3).

4. Connect for a moment a wire from the solenoid connection (terminal) marked Motor to the ground connection (terminal). The pinion will shift to crank position and will stay there until the battery is disconnected.

Typical Pinion Clearance Adjustment
(4) Shaft nut. (5) Pinion. (6) Pinion clearance.

5. Push the pinion toward the commutator end to remove free movement.

6. Pinion clearance (6) must be 8.3 to 9.9 mm (.33 to .39 in).

7. To adjust pinion clearance, remove plug and turn nut (4).

8. After the adjustment is completed, install the plug over adjustment nut (4) and install connector (1) between the MOTOR terminal on the solenoid and the starting motor.

Air Starting System

Pressure Regulating Valve

Pressure Regulating Valve (Typical Illustration)
(1) Adjustment screw. (2) Regulator inlet. (3) Regulator outlet.

To check and adjust the pressure regulating valve, use the procedure that follows:

1. Drain the line to the pressure regulating valve or drain the air storage tank.

2. Disconnect the regulator from the starter control valve.

3. Connect an 8T0849 Pressure Indicator to regulator outlet (3).

4. Put air pressure in the line or tank.

5. Check the pressure.

6. Adjust the pressure regulating valve to ... 690 to 1030 kPa (100 to 150 psi)

7. Remove the air pressure from the line or tank.

8. Remove the 8T0849 Pressure Indicator and connect the air pressure regulator to the line to the air starting motor.

Each engine application will have to be inspected to get the most acceptable starting results. Some of the factors that affect regulating valve pressure setting are: attachment loads pulled by engine during starting, ambient temperature conditions, oil viscosity, capacity of air reservoir, and condition of engine (new or worn).

The advantage of setting the valve at the higher pressures is increased torque for starting motor and faster rotation of engine. The advantage of setting the valve at the lower pressures is longer time of engine rotation for a given capacity of supply air.

Lubrication

Always use an air line lubricator with these air starting motors.

For temperatures above 0°C (32°F), use a non detergent 10W engine oil.

For temperatures below 0°C (32°F), use air tool oil.

Air Starting Motor

Components Of The Air Starting Motor
(1) Motor housing cover. (2) Plug. (3) Plug. (3A) Plug. (6) Bolt (cap screw). (7) Lockwasher. (8) Gasket. (9) Rotor rear bearing. (10) Bearing retainer. (11) Rear end plate. (12) Cylinder. (13) Dowel. (14) Rotor vane. (15) Rotor. (16) Front end plate. (17) Rotor front bearing. (18) Motor housing. (19) Gear case gasket. (20) Rotor pinion. (21) Rotor pinion retainer. (22) Gear case. (23) Bearing rejecting washer. (24) Rear bearing (for the drive shaft). (25) Drive gear. (25A) Thrust washer. (26) Key (for the drive gear). (27) Front bearing (for the drive shaft). (28) Gear case cover. (29) Grease seal (for the drive shaft). (30) Cover seal. (31) Piston seal. (32) Bolt. (33) Lockwasher. (34) Drive shaft. (35) Drive shaft collar. (36) Piston. (36A) Piston ring. (37) Shift ring. (38) Shift ring retainer. (39) Shift ring spacer. (40) Piston return spring. (41) Return spring seat. (42) Starter drive (pinion). (43) Lockwasher. (44) Bushing (for the bolts). (45) Drive housing. (46) Drive housing bushing. (47) Oiler felt (for the bushing). (48) Oiler plug.

Rear View Of The Cylinder And Rotor For Clockwise Rotation
(12) Cylinder. (15) Rotor. (A) Air inlet passages. (B) Dowel hole.

Air Starting Motor
(6) Bolt. (12) Cylinder. (15) Rotor. (16) Front end plate. (22) Gear case. (25) Drive gear. (28) Gear case cover. (29) Grease seal. (32) Bolt. (34) Drive shaft. (35) Drive shaft collar. (42) Starter drive (pinion). (45) Drive housing. (49) Air inlet. (50) Deflector (air outlet). (51) Mounting flange (on the drive housing).

Cylinder (12) must be assembled over rotor (15) and on front end plate (16) so dowel hole (B) and inlet passages (A) for the air are as shown in the rear view illustration of the cylinder and rotor. If the installation is not correct, starter drive (42) will turn in the wrong direction.

Tighten the bolts (6) of the rear cover in small increases of torque for all bolts until all bolts are tight 30 ± 5 N·m (22 ± 4 lb ft).

Put a thin layer of lubricant on the lip of seal (29) and on the outside of drive shaft collar (35), for installation of drive shaft (34). After installation of the shaft through gear case cover (28) check the lip of grease seal (29).

It must be turned correctly toward drive gear (25). If the shaft turned the seal lip in the wrong direction, remove the shaft and install again. Use a tool with a thin point to turn the seal lip in the correct direction.

Tighten bolts (32) of the drive housing in small increases of torque for all bolts until all bolts are tight 11.3 N·m (100 lb in).

Check the motor for correct operation. Connect an air hose to motor air inlet (49) and make the motor turn slowly. Look at starter drive (42) from the front of drive housing (45). The pinion must turn clockwise.

Connect an air hose to the small hole with threads in drive housing (45), nearer gear case (22). When a little air pressure goes to the drive housing, starter drive (42) must move forward to the engaged position. Also, the air must get out through the other hole with threads nearer mounting flange (51).