M11 Plus Series Engines Operation and Maintenance Manual – Coolant Temperature Above Normal – Gradual Overheat

Coolant level is below specification

Inspect the engine and cooling system for external coolant leaks. Repair if necessary. Add coolant. Refer to Procedure 008-066 (Coolant Level) in Section 3.

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 a Cummins Authorized Repair Location.

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 Procedure 101-015 (Operating the Engine) in Section 1.

Cooling system hose are collapsed, restricted, or leaking

Inspect the cooling system hoses for restrictions, obstructions, and leaks. Refer to a Cummins Authorized Repair Location.

Fan drive belt or water pump belt is broken

Check the fan drive belt and water pump belt. Replace the belts if necessary. Refer to Procedure 018-005 (Drive Belt Tension) in Section V.

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.

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

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

Supplemental coolant additive (SCA) level is above specification or the coolant is overconcentrated with antifreeze

Check the SCA level. Verify the antifreeze concentration. Refer to Procedure 008-046 (Supplemental Coolant Additive (SCA) and Antifreeze Concentration) in Section 4.