Introduction
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The connection of battery cables to a battery and the disconnection of battery cables from a battery may cause an explosion which may result in injury or death. The connection and the disconnection of other electrical equipment may also cause an explosion which may result in injury or death. The procedures for the connection and the disconnection of battery cables and other electrical equipment should only be performed in a nonexplosive atmosphere. |
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Troubleshooting can be difficult. To repair the problem, refer to the possible causes and then refer to the corrective actions that are listed. Refer to your engine's Troubleshooting module for more information.
This list of problems, causes, and corrections will only give an indication of the location of a possible problem. This will also list the type of repairs that are needed.
Service personnel may remember similar complaints which were corrected by a previous method of troubleshooting. A similar complaint can have a different cause.
Get a good description of the problem from the operator and/or the person that operates the engine. Knowing the details of the problem can save time. This will make the repair job faster and easier.
Troubleshooting Problems
Combustion Noise
Probable Cause
Low Quality of Fuel or Water in the Fuel - Refer to Testing and Adjusting, "Fuel Quality - Test". Also, refer to Operation and Maintenance Manual, "Fuel Recommendations" for fuel specifications.
Incorrect Timing Position Sensor Calibration - Refer to Troubleshooting for more information.
Fuel Consumption Too High
Probable Cause
Low Quality of Fuel, or Water in the Fuel - Refer to Testing and Adjusting, "Fuel Quality - Test". Refer to Operation and Maintenance Manual, "Fuel Recommendations" for fuel specifications.
Fuel System Leaks - Inspect the fuel system for leaks. As needed, make repairs or replacements.
Excessive Idle Time - The engine should be shut off when the engine is not active.
Fuel and Combustion Noise (knock) - Refer to your engine's Troubleshooting module for more information.
Incorrect Timing Position Sensor Calibration - Refer to your engine's Troubleshooting module for more information.
Excessive Black Smoke
Probable Cause
Not Enough Air for Combustion - Check for a plugged air cleaner element or for blockage in the air lines. Refer to Testing And Adjusting for the procedures to check inlet manifold pressure and aftercooler core leakage.
Incorrect Timing Position Sensor Calibration - Refer to Electronic Troubleshooting for more information.
Too Much White Smoke
Probable Cause
Engine Misfire - Refer to Electronic Troubleshooting for more information.
Incorrect Timing Position Sensor Calibration - Refer to Electronic Troubleshooting for more information.
Coolant in the Combustion System - White smoke can also be caused from the following problems.
- Coolant in the combustion chamber
- A cracked cylinder head
- A cracked cylinder liner
- A faulty cylinder head gasket
Too Much Blue Smoke
Probable Cause
High Engine Oil Level - Do not put too much oil in the crankcase. If the oil level in the crankcase increases during engine operation, check for fuel dilution of the engine oil. If fuel dilution is detected, check for leaks in the injector sleeves. Also check fuel injectors that may be worn or damaged.
Failed Turbocharger Oil Seal - Check the inlet manifold and the aftercooler core for oil. The turbocharger should be repaired or replaced.
Worn Valve Guides - See the Specifications module for the maximum permissible wear of the valve guides.
Worn Piston Rings - Worn piston rings and/or cylinder walls can be the cause of blue smoke and a loss of compression. Make a visual inspection of the cylinder walls and the piston rings. If necessary, measure the cylinder walls and the piston rings. Refer to the Specifications module for the specifications of the cylinder and the piston ring.
Note: High wear at low hours is normally caused by dirt. This dirt comes into the engine with the inlet air.
Low Oil Pressure
Probable Cause
Low Engine Oil Level - Check the engine oil level and fill to the proper level.
Oil Leaks - Check for a loose oil filter or for loose oil supply lines. Check the crankshaft seals and the gaskets for the engine.
Dirty Oil Filter or Plugged Oil Cooler Core - Check the operation of the bypass valve for the filter. As required, install new oil filter elements. Clean the oil cooler core or install a new oil cooler core. Remove the dirty oil and fill the engine with clean oil to the correct level.
Diesel Fuel in the Lubricating Oil - The reason may be an internal leak or worn piston rings. Make repairs, as needed. Remove any oil that contains diesel fuel. Install new oil filters and fill the engine with clean oil to the correct level.
Excessive Clearance Between Rocker Arm Shaft and Rocker Arms - Check for the correct lubrication at the valve train. Install new parts, as needed.
Oil Pump Suction Pipe - If the suction pipe is plugged, clean or replace the pipe. If the pipe is damaged, replace the pipe. Recheck the engine oil pressure.
Oil Pump Relief Valve - Clean the valve and the housing. Install new parts, as required.
Faulty Oil Pump - Replace the oil pump.
Too Much Clearance Between Camshaft and Camshaft Bearings - Inspect the bearings and the camshaft for excessive wear. Replace the worn engine components.
Too Much Clearance Between Crankshaft and Crankshaft Bearings - Inspect the bearings and the crankshaft journals for excessive wear. Replace the worn engine components.
Too Much Bearing Clearance for Idler Gear - Inspect the bearings and the idler gear for excessive wear. Replace the worn components.
Piston Cooling Jets - Inspect the piston cooling jets. If the cooling jets are plugged, clean the jets. Replace cooling jets that have been damaged.
Faulty Oil Pressure Gauge - Replace the oil pressure gauge.
Engine Overheating
Probable Cause
Low Coolant Level - A sufficient amount of coolant will not flow through engine's cooling system if the coolant level is too low. The lack of coolant flow will not adequately dissipate the necessary heat from the engine. Low coolant level can be due to leaks or by improperly following the filling procedure. Refer to Operation and Maintenance Manual, "Cooling System Coolant Level - Check" for information that relates to cooling system maintenance.
Faulty Temperature Gauge - A temperature gauge which does not work correctly will not show the correct temperature. A temperature gauge can show that the coolant temperature is too hot. This can happen even when other conditions are normal. Install a 4C-6500 Digital Thermometer in order to check the temperature of the cooling system.
Dirty Heat Exchanger - Check for restrictions which will prevent the flow of engine coolant through the heat exchanger. Check the heat exchanger for the following items. These items will prevent the free flow of coolant.
- Debris
- Dirt
- Deposits on the inside of the heat exchanger core
Drive Belts that are Loose or Worn - A fan drive belt that is loose can cause a reduction in the flow of air around the engine. Adjust the belts according to the Belt Tension Chart that is shown within this module.
Leaking or Restricted Coolant Hoses - Worn hoses with leaks can normally be seen. Hoses that are soft or damaged can collapse during operation. This will cause a restriction in the flow of coolant. Hoses become soft and/or get cracks through normal use. Hoses that are poorly routed may become kinked. Hoses that are kinked will restrict the flow of coolant. Hoses that are rubbing against engine components will eventually leak. Reroute any hoses that are kinked or hoses that show signs of rubbing. The inside of the hose can become loose, and the loose particles can cause a restriction in the flow of coolant. Refer to Operation and Maintenance Manual, "Hoses and Clamps - Inspect/Replace" for information that is related to the inspection of hoses.
Shunt Line Restriction - A restriction of the shunt line from the expansion tank to the cooling system's water pump will cause a reduction in the water pump efficiency. A shunt line that is not correctly installed will also reduce efficiency. The result will be low coolant flow and overheating of the engine.
Faulty Water Temperature Regulator (Thermostat) - Above normal heating can be caused by a regulator that does not open or a regulator that opens part of the way. Refer to Testing And Adjusting, "Cooling System - Test" for the procedure to test a water temperature regulator.
Faulty Water Pump - A water pump with an impeller wheel that has excessive backlash will not provide adequate flow for the cooling system. This may also cause damage to the internal components of the water pump. Test the water pump's impeller for the proper end play movement. Refer to Specifications, "Water Pump" for information that relates to the proper clearance for the water pump impeller.
Air in the Cooling System - Air can get into the cooling system in different ways. Refer to the following common causes:
- Filling the cooling system incorrectly
- Combustion gas that leaks into the system
Combustion gas can get into the system through internal cracks, a cylinder head that is damaged, or through faulty cylinder head gaskets. Air in the cooling system causes a reduction in coolant flow and bubbles in the coolant. Air bubbles prevent the transfer of heat from the engine parts to the coolant. Air bubbles in the coolant can cause cavitation to occur in the water pump. Cavitation will damage the water pump over time. Use the following information in order to test the cooling system for combustion gases.
The cooling system pressurizing pump may be used to quickly identify combustion gas leakage in the cooling system. The cooling system should be filled to the proper level prior to testing.
Note: The pressurizing pump does not have an automatic pressure relief. The cooling system may be damaged if the pressure is allowed to exceed 103 kPa (15 psi).
- Operate the engine without the pressure cap until the thermostats become open. As the thermostats open, engine coolant will begin to circulate through the heat exchanger chamber. Replace the pressure cap at this time.
- Install the 9S-8140 Pressurizing Pump onto the cooling system. Pressurize the cooling system to 35 to 50 kPa (5 to 7 psi).
- Adjust the engine rpm to the rated engine speed. Monitor the cooling system pressure during 10 minutes of engine operation.
- If the pressure remains below 75 kPa (11 psi), then a combustion leak into the cooling system is not suspected.
- If the pressure rises above 75 kPa (11 psi), then use the pressurizing pump to reduce the cooling system pressure to 35 to 50 kPa (5 to 7 psi). Allow the engine to continue to run.
If the cooling system pressure again rises 75 kPa (11 psi) in a 10 minute time period, an internal combustion leak is suspected.
Locate the source of the air or the gas that is leaking into the cooling system and correct, as needed.
Undersized Heat Exchanger - If the heat transfer characteristics of the heat exchanger is not adequate for the engine application, the engine will overheat. This will cause the engine to run at higher than normal temperatures. Make sure that the size of the heat exchanger is adequate.
High Ambient Air Temperature - The outside temperature can be too high for the rating of the cooling system. Ensure that the design of the cooling system is adequate for the engine's application.
Operating at High Altitude - The cooling capacity of the cooling system diminishes if the engine is operated at high altitudes. A pressurized system that is large enough to keep the coolant from boiling must be used for these applications.
Low Speed Operation of the Engine - Lugging causes the engine rpm, rpm of the water pump, and the rpm of the cooling fan to be below the engine's rated speed. This low rpm causes a reduction in air flow around the outside of the engine. This also causes a reduction in the flow of coolant through the cooling system. The combination of less air and less coolant flow during the high input of fuel will cause above normal heating of the engine.
Air Inlet Restriction - Higher cylinder temperatures can be caused by a restriction of the air that is coming into the engine. The higher cylinder temperatures must be dissipated through the cooling system. Refer to Testing and Adjusting, "Air Inlet and Exhaust System - Inspect" for information that relates to testing for air inlet restriction.
Exhaust Restriction - Higher cylinder temperatures can be caused by a restriction of the engine's exhaust system. The higher cylinder temperatures must be dissipated through the cooling system. Refer to Testing and Adjusting, "Air Inlet and Exhaust System - Inspect" for information that relates to testing for exhaust restriction.
Engine Operating Temperature Below Normal
Probable Cause
Long Idle Periods - When the engine is running with no load, only a small quantity of fuel is burned. Very little heat is being generated by the engine.
Very Light Load - Very light loads can cause overcooling. The overcooling is caused by the engine's capacity to generate heat during light load conditions.
Faulty Water Temperature Regulator (thermostat) - A regulator that is stuck open will cause overcooling.
External Coolant Leaks
Probable Cause
Leaks in Hoses or Hose Connections - Check all hoses and connections for visual signs of leakage. If no leaks are seen, look for damage to hoses or loose clamps.
Leaks in the Heat Exchanger - Pressurize the engine cooling system with the 9S-8140 Pressurizing Pump and check for leaks. Refer to Testing And Adjusting, "Cooling System - Test".
Leaks at the Water Pump - Check the water pump for leaks before starting the engine. Start the engine and look for leaks. If the water pump leaks, repair the water pump or install a new water pump. A small amount of seepage at the water pump's weep hole is acceptable. This seepage is used to lubricate the water pump's shaft seal.
Cylinder Head Gasket Leakage - Look for leaks along the surface of the cylinder head gasket. Install a new head gasket if leaks are visible.
Coolant Leaks At The Overflow Tube
Probable Cause
Faulty Pressure Cap or Relief Valve - Check the sealing surfaces of the pressure cap and the filler tube. Make sure that the cap is sealing correctly. Check the opening pressure and the sealing ability of the pressure cap or relief valve with the 9S-8140 Pressurizing Pump and check for leaks. Refer to Testing And Adjusting, "Cooling System - Test".
High Engine Operating Temperature - A coolant temperature that is too high will increase the cooling system pressure. The pressure will be high enough to open the relief valve. This will cause a coolant loss through the overflow tube. Refer to "Engine Overheating".
Faulty Expansion Tank - Ensure that the expansion tank is installed correctly. Ensure that the expansion tank is the correct size according to the recommendations of the manufacturer.
Cylinder Head Gasket Leakage or Crack(s) in the Cylinder Head or the Cylinder Block - While the engine is running, remove the pressure cap. 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 the cylinder head, the cylinder liners and the head gasket surface of the cylinder block for cracks. When you reinstall the cylinder head, use a new head gasket, a new spacer plate gasket, new water seals, and new O-ring seals.
Coolant Leakage Inside Engine
Probable Cause
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.
Crack(s) in the Cylinder Head - Cracks in the upper surface of the cylinder head, or in an area between a water passage and an opening into the crankcase can allow coolant to get into the crankcase.
Crack(s) in the Cylinder Block - Cracks in the cylinder block between a water passage and the crankcase will allow coolant to get into the crankcase.