Refer to Testing and Adjusting for information on determining the cause of this condition.
Probable Causes
- Coolant level
- Combustion gases in the cooling system
- Water temperature regulators
- Restriction in the cooling system
- Coolant temperature gauge
- Water pump
- Excessive load on the system
Recommended Actions
Coolant Level
- Inspect the coolant level. If necessary, add coolant.
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Pressurized System: Hot coolant can cause serious burns. To open the cooling system filler cap, stop the engine and wait until the cooling system components are cool. Loosen the cooling system pressure cap slowly in order to relieve the pressure. |
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- Check the cooling system for leaks. Repair any leaks immediately.
Combustion Gases in the Cooling System
Inspect the coolant for presence of bubbles. If bubbles are present, combustion gases may be entering the cooling system.
Water Temperature Regulators
Check the water temperature regulators for correct operation. Refer to Testing and Adjusting, "Cooling System" for the proper procedure. If necessary, replace the water temperature regulators. Refer to Disassembly and Assembly, "Water Temperature Regualtor - Remove and Install" for more information.
Restriction in the Cooling System
The following cooling systems may not be operating properly.
- Raw water circuit for the heat exchanger
- Keel cooler
Raw Water Circuit for the Heat Exchanger
- Visually inspect the circuit for collapsed hoses and/or other restrictions.
- Clean the circuit and make the necessary repairs to the circuit.
Keel Cooler
- Visually inspect the circuit for collapsed hoses and/or other restrictions.
- Clean the circuit and make the necessary repairs to the circuit.
Coolant Temperature Gauge
Compare the reading for the coolant temperature from the Caterpillar Electronic Technician (Cat ET) to the reading for the coolant temperature from a mechanical gauge.
Water Pump
Inspect the water pump impeller for damage and/or erosion. If necessary, repair the water pump or replace the water pump.
Excessive Load on the System
Reduce the load and verify that the condition does not reoccur.