D346, D348 AND D349 INDUSTRIAL ENGINES Caterpillar

Low Oil Pressure Checks:

If the low oil pressure shutoff control has stopped the engine, make the following checks:

1. Check the water temperature gauge. Determine if the engine was overheated. Check for external water leaks.

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Beware of steam or scalding water. Do not attempt to loosen the radiator cap until the temperature gauge indicates the coolant has sufficiently cooled. Then, loosen the cap slowly.

2. Check the oil level. Oil level must be between the ADD and FULL marks on the side of the dipstick stamped CHECK WITH ENGINE STOPPED.

3. If the oil level is below the ADD mark, check for oil spray and/or oil accumulations. If any are found, have the necessary repairs made. Before starting, add oil to the FULL mark.

4. Reset the shutoff control.

5. Remove the load and start the engine at its slowest speed. Be prepared to shut the engine down manually.

6. Be alert for unusual sounds or noises. If the engine knocks, stop the engine immediately and call your Caterpillar dealer.

7. If the engine blows excessive black exhaust or has excessive crankcase blow-by, the engine may need reconditioning. Stop the engine and call your Caterpillar dealer.

8. If the engine runs satisfactorily, observe the oil pressure gauge. If satisfactory pressure is not indicated, shut the engine down; call your Caterpillar dealer.

9. If proper oil pressure is registered, check to see if the reset knob has moved to the run position. If the knob does not move, stop the engine. Check the shutoff control, the oil line, and the oil pressure gauge. Have necessary repairs made.

10. If the oil pressure gauge registers normal oil pressure, if the knob on the shutoff control moves to the run position, and if the engine operation is otherwise satisfactory, determine if the high water temperature shutoff may have shut down the engine.

High Water Temperature Checks - Engine Running:

1. Determine if the load was too great for the engine: Reduce the load and allow the engine to cool while running.

2. If pressure steam or water leaks are visible, remove the load and stop the engine. Have necessary repairs made.

3. Check for collapsing or deteriorated water hoses. Have repairs made.

4. Check for noisy water pump operation. Have necessary repairs made.

5. Refill the cooling system with a solution of water and permanent type antifreeze if below freezing temperatures are expected; or with a solution of approved water and Caterpillar Corrosion Inhibitor. Follow the instructions on the container.

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DO NOT remove the pressure cap on an overheated engine. The coolant is under pressure and relieving the pressure will cause the coolant to flash into steam. Serious flash burns and engine damage can result. If necessary, reduce pressure in a surge tank by pouring warm water on top of the tank. Never add cold water to a hot engine.

NOTE: If there is adequate coolant in the cooling system, gradual cooling is preferred by running the engine at half speed. This eliminates hot spots in the engine, and possible failure.

High Water Temperature Checks - Engine Stopped and Cold:

1. Check coolant level. Determine if the coolant has proper antifreeze protection. A 50-50 solution of permanent type antifreeze and approved water will give protection below -20°F (-29°C).

2. Check to be sure the raw water valve has been opened.

3. Check water pump drive belts for proper tension; see the LUBRICATION AND MAINTENANCE PROCEDURES topic, Fan Belts.

4. Check engine room vents and/or louvers. Be sure the engine is receiving sufficient air.

5. Be sure temperature regulators are operating at proper temperature range.

6. Inspect all water hoses carefully for collapsing, external and internal failures. Replace hoses as required.

7. Have the cooling system cleaned.