Cummins N14 STC, Celect, Celect Plus – Service Manual Coolant Temperature Above Normal – Gradual Overheat

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF in the CELECT Plus™ Systems Troubleshooting and Repair Manual, Bulletin 3666130, or Section TF in the CELECT™ Systems Troubleshooting and Repair Manual, Bulletin 3666084, for fault code troubleshooting.

Coolant level is below specification

Check the coolant level. Check for an external leak. Refer to Refer to Procedure 008-018 in Section 8. Sample the lubricating oil and have a laboratory check for coolant in the oil (internal leak).

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 Procedure 010-027 in Section 10 and Procedure 008-042 in Section 8.

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 OEM service manual.

Cooling system hose is collapsed, restricted, or leaking

Inspect the hoses. Refer to Procedure 008-045 in Section 8.

Fan drive belt is loose

Check the belt tension and tighten, if necessary. Refer to Procedure 008-002 in Section 8.

Lubricating oil level is above or below specification

Check the oil level. Add or drain oil, if necessary. Refer to Procedure 007-037 and Procedure 007-009 in Section 7.

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, as necessary. Refer to Procedure 008-038 in Section 8 and the OEM service manual.

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

Check the radiator pressure cap. Refer to Procedure 008-047 in Section 8.

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 008-047 in Section 8.

Intake manifold temperature gauge is malfunctioning, if equipped

Refer to the Intake Manifold Air Temperature Above Specification troubleshooting symptom tree in Section TS.

Coolant temperature gauge is malfunctioning

Test the temperature gauge. Repair or replace the gauge, if necessary. Refer to 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 in Section 8.

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

Inspect the radiator shutters. Repair or replace if necessary. Refer to Procedure 008-049 in Section 8. Check the shutterstat setting.

Radiator swing check valve is malfunctioning (if equipped)

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

Fan drive or fan controls are malfunctioning

Check the fan drive and controls. Refer to Procedure 008-026, Procedure 008-027, or Procedure 008-028 in Section 8.

Air or combustion gases are entering the cooling system

Check for air or combustion gases in the cooling system. Refer to Procedure 008-019 in Section 8.

Water pump is malfunctioning

Check the water pump for correct operation. Replace the water pump, if necessary.

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 the OEM service manual.

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

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

Engine is overfueled

Check the engine fuel rate. Refer to Procedure 014-005 in Section 14.

Vehicle cooling system is not adequate

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

Torque converter cooler disc is not installed correctly

Check the disc for correct installation. Refer to the OEM service manual.