Centinel System – Repair Manual – Coolant Temperature Above Normal – Gradual Overheat

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF in the Troubleshooting and Repair Manual, CM870 Electronic Control System, Signature and ISX Engines, Bulletin 4021334, or the Troubleshooting and Repair Manual, Electronic Control System, Signature, ISX and QSX Engines, Bulletin 3666259, or the Troubleshooting and Repair Manual, Power Generation Control Systems QSX15, QSK23, QSK45, QSK60, QSK78, and QST30 Series Engines, Bulletin 4021419 for fault code troubleshooting.

Coolant level is below specification

Inspect the engine and cooling system for external coolant leaks. Repair if necessary. Add coolant. Refer to Procedure 008-018.

Cold weather radiator cover or winterfront is closed

Open the cold weather radiator cover or the winterfront. Maintain a minimum of 784 cm² [122 in²] or approximately 28 x 28 cm [11 x 11 in] of opening at all times. Refer to the Cold Weather Starting Aids, Procedure 101-005 in Section 7 of the Operation and Maintenance Manual Signature and ISX Engines, Bulletin 3666257 or Winterfronts in Section 1 of the Operation and Maintenance Manual Signature and ISX Engines, Bulletin 3666311.

Fan drive belt is loose

Check the automatic belt tensioner. Refer to Procedure 008-002 and 008-080.

Charge air cooler fins, radiator fins, or air conditioner condenser fins are damaged or obstructed with debris

Inspect the charge air cooler, air conditioner condenser, and radiator fins. Clean, if necessary. Refer to Procedures 010-027, 008-042 and the OEM service manual.

Fan drive or fan controls are malfunctioning

Check the fan drive and controls. Refer to Procedure 008-027.

Radiator cap is not correct, is malfunctioning, or has low-pressure rating

Check the radiator pressure cap. Refer to Procedure 008-047.

Radiator shutters are not opening completely, or the shutterstat setting is wrong

Inspect the radiator shutters. Repair or replace if necessary. Check the shutterstat setting. Refer to the OEM service manual.

Coolant temperature gauge is malfunctioning

Test the temperature gauge. Repair or replace the gauge, if necessary. Refer to Procedure 008-049 and the OEM service manual.

Cooling system hose is collapsed, restricted, or leaking

Inspect the hoses. Refer to Procedure 008-045.

Fan shroud is damaged or missing or the air recirculation baffles are damaged or missing

Inspect the shroud and the recirculation baffles. Repair, replace, or install, if necessary. Refer to Procedure 008-038 and the OEM service manual.

Fill line or vent lines are restricted, obstructed, or not routed correctly

Check the vent lines and the fill line for correct routing and for restriction. Refer to Procedure 008-017 and the OEM service manual.

Thermostat is not correct or is malfunctioning

Check the thermostat for the correct part number and for correct operation. Refer to Procedure 008-013.

Intake manifold air temperature is above specification

Refer to the Intake Manifold Air Temperature Above Specification symptom tree.

Lubricating oil level is above or below specification

Check the oil level. Add or drain oil, if necessary. Refer to Procedure 007-037. Check the dipstick calibration. Refer to Procedure 007-009.

Radiator swing check valve is malfunctioning (if equipped)

Check the swing check valve for correct operation. Refer to the OEM service manual.

Water pump is malfunctioning

Check the water pump for correct operation. Replace the water pump if necessary. Refer to Procedure 008-062.

Radiator core is internally obstructed or damaged, or the check valve or J-tube is malfunctioning

Inspect the radiator and clean if necessary. Refer to Procedure 008-042.

Check valve is damaged (with remote-mounted engine coolant heater)

Inspect the check valve. Replace if necessary. Refer to the OEM service manual.

Air or combustion gases are entering the cooling system

Check for air or combustion gases in the cooling system. Refer to Procedure 008-019.

Torque converter is malfunctioning

Check the torque converter. Refer to the OEM service manual.

Vehicle cooling system is not adequate

Verify that the engine and vehicle cooling systems are using the correct components. Refer to the OEM service manual.