D346 MARINE ENGINE Caterpillar


Operating Engine And Marine Gear

Usage:

Instrument Panel Gauges

After the engine starts, and at frequent intervals while the engine is operating, the gauges should be observed. Determine the normal reading for each gauge. Investigate the cause whenever there is a significant change in the reading.

Your engine may be equipped with calibrated gauges. Periodic monitoring and recording of the gauge readings will provide a performance history of the engine. As certain conditions develop, a change in a reading will indicate a problem is developing. The necessary repairs can be scheduled before the failure and unexpected downtime occurs.


INSTRUMENT PANEL GAUGES

1. Tachometer.

2. Left inlet manifold temperature.

3. Right inlet manifold temperature.

4. Left and right exhaust manifold temperatures.

5. Engine oil temperature.

6. Engine jacket water temperature.

7. Engine oil pressure.

8. Fuel pressure.

9. Marine gear oil temperature.

10. Marine gear oil pressure.

11. Ammeter.


GAUGE
8. Fuel Pressure.

Tachometer

The tachometer (1) indicates engine RPM. When the governor control lever is moved to the full speed position, without load, the engine is running at high idle. When the governor control lever is moved to the full speed position and load is applied, the engine will slow slightly to full load speed. The high idle RPM and the full load RPM are stamped on the engine's Altitude Information Plate. The engine can be operated between these two speed limits for long periods of time without shortening engine life.

If the engine speed drops below full load speed with the governor control lever positioned in the full governed position, the engine will be operating in a lug condition. Lugging of a marine engine for long periods of time will require servicing of the engine more frequently than is stated in the LUBRICATION AND MAINTENANCE CHART; and shorter life of engine components can be expected.

Engine Oil Pressure

Oil pressure reading (7) will be greatest after starting a cold engine. Oil pressure will decrease as the engine warms while idling. As the engine speed is increased to full load speed, oil pressure will increase into the NORMAL range and stabilize.

If the gauge reading fluctuates:

1. Remove the load.
2. Reduce engine speed to low idle.
3. Check the oil level. Maintain the oil level between the ADD and FULL marks on the dipstick. If the reading continues to fluctuate, contact your Caterpillar dealer.

If the gauge reading decreases at rated speed, the oil filter elements may be plugged. Check the oil filter service indicator (where provided) or change the oil filter elements.

IF OIL PRESSURE DROPS RAPIDLY AT RATED SPEED, STOP THE ENGINE IMMEDIATELY.

Engine Jacket Water Temperature

The water temperature reading (6) may vary according to load, but should never exceed the boiling temperature for the pressurized system being used.

If the engine operates with the indicator in the HOT range and steam becomes apparent:

1. Reduce the load and speed.
2. Inspect for pressure steam or water leaks. Determine if the engine must be shut down immediately; or if the engine can be safely cooled by reducing the load.


NOTICE

Do not add cold water to a hot engine. Cracking of engine components may occur. Allow the engine to cool; then add coolant.


The engine operating temperature should be approximately 200°F (95°C). If the temperature gauge reading continues to register in, or near, the cold range - approximately 170°F (75°C):

1. Check the temperature regulators for proper temperature range; replace them if necessary.
2. Check the water temperature gauge for accuracy.

Fuel Pressure

The fuel pressure gauge (8) indicates pressure of the filtered fuel. As the fuel filter becomes plugged, there should be a noticeable reduction in the engine's performance. If the fuel filter gauge registers in the OUT range, clean the primary fuel filter if so equipped, and install new fuel filter elements. See the LUBRICATION AND MAINTENANCE PROCEDURES.

In cold weather, paraffin crystals can form in the fuel and plug the fuel filter. If this occurs, fuel that has a lower CLOUD POINT must be used. See your fuel distributor.

Ammeter

The ammeter (11) should indicate just to the right of zero (in the "+" range) when the engine is warm and running at rated speed. If the gauge registers to the left in the "-" range) as the engine speed is increased, determine and correct the cause.

Engine Oil Temperature

The purpose of the oil is to lubricate all moving parts inside the engine, and to cool (remove the heat from) the pistons, liners and bearings. The oil cooler transfers the heat in the oil to the engine jacket water. If the cooling system cannot expel the necessary heat from the water, the engine oil cannot be properly cooled. Above normal oil temperature (5) indicates a heat problem has occurred with the engine and/or cooling system and a problem can occur with cylinder heads, liners, pistons or bearings.

Exhaust Temperature Gauge

This gauge (4), measures exhaust gas temperature. On V-engines, temperature readings are taken from both the left and right banks, and the two readings will vary slightly from each other. If the exhaust temperature (4) increases:

1. Check the load on the engine. Running the engine below rated full load RPM for long periods of time causes excessive exhaust temperatures, overheating of the engine's cooling system, and possible engine damage. Reduce the load if necessary.
2. Check the air cleaner service indicator or air cleaner pressure gauge; the air cleaner element may be plugged. Stop the engine and service the air cleaner if necessary.
3. After the engine has been stopped, check the tightness of the inlet and exhaust manifold bolts. These bolts must be tight.

Inlet Air Temperature Gauge

As the inlet air increases in temperature, the air expands, less fuel is burned in the cylinders; and less horsepower is developed. As a result, at full load governor position with a full load, the engine may be overloaded.

If excessive air inlet temperature (2) and (3) occurs:

1. Reduce the load.
2. Determine if there is an adequate supply of cool air to the engine air inlet. Be sure hot air isn't being drawn into the air cleaner.
3. Check the water temperature gauge. Determine if the aftercooler water system is capable of cooling the air in the aftercooler. Engine power ratings are based upon the water entering the aftercooler at a maximum temperature of 85° F (29°C) for sea water, or 130° F (54°C) for engine jacket water.
4. Listen for unusual water pump noises. Be sure the V-belts and the water pump are properly operating. Check belt adjustment when the engine is stopped.

Marine Gear Oil Temperature

The marine gear oil temperature (9) depends upon the temperature and the quantity of water pumped through the marine gear oil cooler. Caterpillar 7200 Series Marine Gears have sea water pumped through the oil cooler. The normal marine gear oil temperature range is 140°F to 175°F (60°C to 79°C). Twin Disc Marine Gears, supplied by Caterpillar Tractor Co., have engine jacket water pumped through the oil cooler, and the normal marine gear oil temperature range is 160°F to 230°F (71°C to 110°C).

If the oil temperature is above the normal operating range:

1. Determine if the high temperature could be caused by severe operation: long periods of trolling, or numerous changes in direction of travel.
2. Check the temperature of the cooling water; determine if the water passing through the oil cooler can absorb the heat from the marine gear oil.
3. Determine if the oil cooler is plugged, if the marine gear oil pump is defective, or if the cooling water system is defective.
4. On Caterpillar 7200 Series Marine Gear, determine if the sea water strainer is plugged, if the sea water pump or lines are defective, or if the oil temperature regulator is defective.

Marine Gear Oil Pressure

Normal oil pressure (10) depends on the temperature and quantity of oil pumped through the oil system. If the marine gear oil is hot, the pressure will be less than if the oil is cold.

If the oil strainer is plugged, or if there is a restriction in either the oil pump, selector valve, or lines, the pressure will be less than the minimum pressure required. If this occurs, the oil temperature will increase, oil pressure will decrease, and clutch wear will be excessive.

If a high oil pressure reading occurs:

1. Check the marine gear oil temperature reading. The excess pressure may be caused by the oil being cold. Allow the oil to warm.
2. If oil temperature is normal and oil pressure is high, either the selector valve is defective, or there is a restriction in the oil line after the selector valve. Contact your Caterpillar dealer.

If a low oil pressure reading occurs:

1. Check the marine gear oil temperature reading. If the oil temperature reading is high, correct the problem(s) as discussed above.
2. Check the marine gear oil level. If the level is low, add oil. Check for oil leaks and make repairs as needed.
3. Determine if the marine gear oil strainer is plugged. Remove the strainer, and clean. See the LUBRICATION AND MAINTENANCE PROCEDURES, Power Coupling System.
4. If the oil temperature is normal, the oil level is normal, the strainer is clean and oil pressure is still low, either the gauge is defective, the line is plugged before the selector valve, the selector valve is defective, or the marine gear oil pump has failed: Contact your Caterpillar dealer.

Air Cleaner Differential Pressure Gauge

This gauge measures the difference of air pressure between the inlet side (dirty side) and the engine side (clean side) of the air filter element. As the element becomes plugged, the difference in pressure between the two sides of the element will increase. As the indicator reading increases to indicate the filter element is dirty, service the air cleaner when the engine is stopped; see the LUBRICATION AND MAINTENANCE PROCEDURES, Air Induction and Exhaust System.

Oil Filter Differential Pressure Gauge

This gauge measures the difference of oil pressure between the inlet side and the outlet side of the oil filter elements. As the element becomes plugged, the difference in pressure between the two sides of the element will increase. As the gauge reading indicates the filter element is becoming plugged, change filter elements when the engine is stopped; see the LUBRICATION AND MAINTENANCE PROCEDURES, Engine Lubrication System.

Large seagoing V-engines may be equipped with a duplex oil filter system which allows changing the oil filter elements while the engine is running. See the LUBRICATION AND MAINTENANCE PROCEDURES for these instructions.

------ WARNING! ------

Only duplex filter systems can be changed with the engine running. To change all other filters, the engine must be stopped.

------WARNING!--------

Observe all gauge readings periodically. Know the normal indication of each gauge. If there is a sudden change, investigate the cause immediately, and make repairs as needed.

Indicators

Air Cleaner Service Indicator

Periodically check the air cleaner service indicator. If the red piston remains in the visible position, the air cleaner element requires servicing. See the LUBRICATION AND MAINTENANCE PROCEDURES.

Oil Filter Change Indicator

On V-engines, periodically check the oil filter change indicator. When the red piston has raised half way in the clear plastic window, change the oil filter elements.

NOTE: The engine is shipped with an opaque covering over the clear plastic window. Be sure this covering is removed.

Marine Gear Operating Procedures

The marine gear selector valve can be manually operated at the marine gear, but is usually operated from the pilot house. Pilot house controls must be adjusted so as to permit full travel of the selector lever on the marine gear, and full engagement of the clutch plates.

NOTE: With the remove controls properly adjusted, periodic clutch adjustment is not required.

To get underway after the engine has started and is warm:

1. Move the marine gear control lever in the desired direction to the fully engaged position.
2. Wait one second to allow complete engagement of the clutch.
3. Gradually increase engine speed as required.

To reverse direction when docking or traveling:

1. Reduce engine speed to low idle.
2. Move the marine gear control lever to the neutral position.
3. Wait two seconds to allow the clutch plates to completely release, and the propeller to stop turning.


NOTICE

When reversing direction of travel, stop at least 2 seconds in the NEUTRAL position to allow the propeller to stop turning. A direct through-shift will cause severe shock loads to the engine, marine gear and hull; and may cause the engine to reverse its rotation. If the engine reverses rotation, the engine and marine gear oil pumps will be running opposite normal rotation and will be pulling oil from the bearings: Severe damage will result.


4. Move the marine gear control lever to the engaged position. Prevent the propeller from stalling or reversing the engine's rotation by gradually increasing engine speed as the clutch is engaged.
5. Allow at least one second to allow complete engagement of the clutch.
6. Gradually increase engine speed as needed.

When the marine gear selector lever is moved to the engaged position, the engine torque must be able to overcome the propeller and drive line inertia, the marine gear inertia and the propeller slip stream torque. On small horsepower engines, the drive line mass and inertia are usually light enough for the operator to control when reversing direction. Careless operation, however, can cause damage to the equipment. On large horsepower engines, a sequenced engine control system may be required. This equipment consists of a throttle boost with a shaft brake as optional equipment.

The throttle boost system momentarily increases engine speed as the marine gear selector lever is moved from NEUTRAL to the engaged position. Upon completion of the clutch engagement, the throttle boost is released and the governor setting regulates the engine speed.

The shaft brake stops the propeller shaft rotation when both clutches are disengaged with the selector lever in the NEUTRAL position. The shaft brake should be able to stop approximately 75% of the full rated shaft torque and should be able to stop the shaft within 3 seconds during a full power reversal.

Engine And Marine Gear Operation

Full Load Operation

Move the governor control to full engine speed. An engine having fuel settings for continuous operation, can operate at full engine speed for long periods of time without shortening engine life.

Pleasure Craft Operation

An engine having pleasure craft fuel settings, should not be operated for a period longer than 5 minutes at full speed. When operated at full speed, the engine should then be operated for as long, or longer, at cruising speed. The engine can be operated at cruising speed for long periods of time without shortening engine life.

Cruising Speed for Pleasure Craft Rated Engines

Recommended cruising speed for your pleasure craft rated engine is dependent upon exterior hull conditions, propeller shaft alignment, and propeller condition. Cruising speed must be determined each day the craft is operated.

To determine the cruising speed for your engine:

1. Start and warm the engine.
2. Gradually increase the speed of the vessel until full speed is reached.
3. Maintain full speed for approximately 4 minutes.
4. Observe the maximum tachometer reading: This is maximum engine speed for the vessel under the existing conditions of the hull and propeller. These conditions can change daily.
5. Reduce engine speed 200 to 300 RPM. This is the recommended cruising speed for your engine under present conditions.
6. If it is necessary to increase engine speed, run at maximum engine speed for 5 minutes or less. Then operate for an equal period of time or longer at cruising speed (or slower) before increasing engine speed again. The slower speed is needed to allow the engine and components to properly cool.


NOTICE

Operating your engine for periods longer than 5 minutes at full engine speed will require the engine and components to be serviced more frequently than instructed in the Lubrication and Maintenance Chart.


Reduced Speed Operation

If the front power take-off is to be operated, or if a slower vessel speed is required, reduce engine speed by moving the governor control lever to the desired speed position. For operation of equipment powered by the front power take-off, see the Operation Instructions for the equipment.

Trolling

The trolling valve is an attachment to the marine gear and operates only in the forward direction. With the trolling valve engaged, engine speed must not exceed 650 RPM for engines with a 1800 RPM full load speed, or 1000 RPM for 2400 RPM engines. The marine gear oil temperature must not exceed 180°F (82°C). It may be desirable to mark the tachometer and oil temperature gauges at these two limits as a warning. Proper monitoring of these gauges is required to prevent overheating of the clutch plates.

Trolling at reduced load for several hours may cause oil consumption and carbon to build in the combustion chamber. This results in poor performance and loss of power. Every 4 hours, load the engine at full speed and burn the carbon from the combustion chamber.

For the operation of other attachments to marine gears for trolling purposes, see the manufacturer's instructions.

Temporary Stopping

For a temporary stop, during which time the engine is to continue running:

1. Reduce engine speed to low idle.
2. If water current conditions permit, shift into neutral.
3. Maintain engine speed at no more than half engine speed position.
4. After 5 minutes, engine speed may be reduced to low idle position if water conditions permit.
5. To resume travel, shift into forward or reverse at low idle speed. Gradually increase engine speed as needed.

Stopping

1. Reduce engine speed to low idle and continue on to anchorage.
2. Shift into neutral and secure the vessel.
3. Increase engine speed to no more than half engine speed. Idle for at least 5 minutes in order to cool the engine.
4. Reduce engine speed to low idle.
5. Check the crankcase oil level while the engine is idling. Maintain the oil level between the ADD and FULL marks on the side of the dipstick stamped CHECK WITH ENGINE RUNNING. See the LUBRICATION AND MAINTENANCE PROCEDURES.
6. Engage the marine gear. Check the marine gear oil level at low idle. Maintain oil level between the ADD and FULL marks on the dipstick. See the LUBRICATION AND MAINTENANCE PROCEDURES. Shift to NEUTRAL.
7. The engine may be stopped by using one of the following engine mounted controls:

Mechanical Governor Control

Pull upward on the hand grip and move the control to the shutoff position.

Air Controls

Push and hold the ON-OFF-STOP switch in the STOP position until the engine stops.

Electric Shutoff Solenoid

Push and hold the ON-OFF-STOP switch in the STOP position until the engine stops.

Woodward UG8 Governor

Turn the load limit knob to "O".

Woodward PSG Governor

Move the lever forward against the stop; hold the lever until the engine stops.

Manual Shutoff Control

Push and hold the control handle until the engine stops.

After Stopping Checks And Procedures

1. Fill the day tank. See the LUBRICATION AND MAINTENANCE PROCEDURES.
2. Drain the sea water system if below freezing temperatures are expected; see the LUBRICATION AND MAINTENANCE PROCEDURES.
3. If below freezing temperatures are expected, allow the engine jacket water expansion tank to cool; then check the coolant for proper antifreeze protection. Add permanent-type antifreeze if required; see LUBRICATION AND MAINTENANCE PROCEDURES.
4. Repair any leaks, correct minor adjustments, tighten loose bolts, etc.
5. Observe the service meter reading. Perform the periodic maintenance as instructed in the LUBRICATION AND MAINTENANCE CHART.


SERVICE METER - 6 Cylinder Engine


SERVICE METER - V-Engine

6. Perform the required periodic maintenance on all other equipment as directed in the equipment manufacturer's instructions.
Back to top
The names Caterpillar, John Deere, JD, JCB, Hyundai or any other original equipment manufacturers are registered trademarks of the respective original equipment manufacturers. All names, descriptions, numbers and symbols are used for reference purposes only.
CH-Part.com is in no way associated with any of the manufacturers we have listed. All manufacturer's names and descriptions are for reference only.