ISBe/ISB Series Engines – Coolant Temperature Above Normal – Sudden Overheat

Electronic fault codes are active

For instructions on how to read active fault codes, refer to Diagnostic Fault Codes in Section 1. If fault codes are active, contact a Cummins Authorized Repair Facility.

Coolant level is below specification

Inspect the engine and cooling system for external coolant leaks. Repair if necessary. Add coolant. Refer to Section 3.

Fan drive belt is broken

Check the fan drive belt. Replace the belt, if necessary. Refer to Section 6.

Cold weather radiator cover or winterfront is closed

Open the cold weather radiator cover or the winterfront. Maintain a minimum of 387 cm² [60 in²] of opening at all times. Refer to Section 1.

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 Section 4.

Coolant temperature gauge is malfunctioning

Test the temperature gauge. Repair or replace the gauge, if necessary.

Cooling system hose is collapsed, restricted, or leaking

Inspect the hoses. Refer to Section 7.

Radiator cap is notcorrect, is malfunctioning, or has low-pressure rating

Check the radiator pressure cap. Refer to the OEM service manual.