ISBe/ISB Series Engines – Coolant Temperature Above Normal – Gradual 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.

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 level is below specification

Inspect the engine and cooling system for external coolant leaks. Repair if necessary. Add coolant. Refer to Section 7.

Coolant mixture of antifreeze and water is notcorrect

Verify the concentration of antifreeze in the coolant. Add antifreeze or water to correct the concentration. Refer to Section 5.

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 the OEM service manual.

Fan drive belt is loose, tight, or notin alignment

Check the fan drive belt. Refer to Section 6.

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.

Lubricating oil level is above or below specification

Check the oil level. Add or drain oil, if necessary. Refer to Section 5.

Lubricating oil is contaminated with coolant or fuel

Change the oil and filters. Refer to Lubricating Oil Contaminatedsymptom tree.

Vehicle cooling system is notadequate

Verify that the engine and vehicle cooling systems are using the correct components. Refer to the manufacturer’s instructions.