TEE 5N9065 - Caterpillar

Note: This is not an electronic system fault.Probable Causes
Heat exchanger
Aftercooler
Coolant level
Radiator cap and/or pressure relief valve
Coolant temperature gauge
Restriction in the coolant system
Water temperature regulator
Coolant pump
Auxiliary water pump
Cylinder head gasketRecommended Actions
Heat Exchanger
Clean the heat exchanger and flush the heat exchanger. Refer to the Operation and Maintenance Manual, "Heat Exchanger - Inspect".Aftercooler
Clean the aftercooler and flush the aftercooler. Refer to the Operation and Maintenance Manual, "Aftercooler Core- Clean/Test".Coolant Level
Inspect the coolant level. If necessary, add coolant.
Check the cooling system for leaks. Repair any leaks immediately.Radiator Cap and/or Pressure Relief Valve
Pressure test the cooling system. Refer to Systems Operation, Testing and Adjusting, "Cooling System" for the correct procedure.
Check that the seating surfaces of the pressure relief valve and the radiator cap are clean and undamaged.
Check operation of the pressure relief valve and/or the radiator cap. If necessary, clean the components and/or replace the components.Coolant Temperature Gauge
Compare the reading for the coolant temperature from the electronic service tool to the reading for the coolant temperature from a calibrated test gauge.Restriction in the Coolant System
Visually inspect the cooling system for collapsed hoses and/or other restrictions.
Check the raw water inlet for a blockage.
Clean the cooling chamber in the exhaust manifold and flush the cooling chamber in the exhaust manifold. Refer to the Operation and Maintenance Manual, "Cooling System Coolant (DEAC) - Change" or the Operation and Maintenance Manual, "Cooling System Coolant (ELC) - Change".Water Temperature Regulator
Check the water temperature regulator for correct operation. Refer to Systems Operation, Testing and Adjusting, "Cooling System" for the proper procedure. If necessary, replace the water temperature regulator. Refer to Disassembly and Assembly, "Water Temperature Regulator - Remove and Install" for more information.Coolant Pump
Inspect the impeller of the coolant pump for damage and/or erosion.
Make sure that the drive gear is not loose on the drive shaft of the coolant pump.
If necessary, replace the coolant pump. Refer to Disassembly and Assembly, "Water Pump - Remove" and Disassembly and Assembly, "Water Pump - Install".Auxiliary Water Pump
Inspect the impeller of the auxiliary water pump for damage and/or erosion.
Make sure that the drive gear is not loose on the drive shaft of the auxiliary water pump.
If necessary, replace the auxiliary water pump. Refer to Disassembly and Assembly, "Auxiliary Water Pump - Remove" and Disassembly and Assembly, "Auxiliary Water Pump - Install".Cylinder Head Gasket
Switch off the engine and allow the engine to cool to below normal working temperature. Remove the pressure cap for the coolant system. Start the engine and inspect the coolant for the presence of bubbles. If bubbles are present in the coolant, combustion gases may be entering the cooling system. Check the cylinder head gasket. Refer to the recommended action for the cylinder head gasket within Troubleshooting, "Coolant in Engine Oil". Check the cylinder head for flatness. Refer to the recommended action for checking flatness of the cylinder head within Systems Operations, "Cylinder Head - Inspect". Fit the pressure cap if there are no bubbles in the coolant.