M11 – Coolant Temperature Above Normal – Gradual Overheat

Symptom Tree  

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 Procedure 008-049 (Radiator Shutter Assembly) in Section 5.


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 101-004 (Cold Weather Starting) in Section 1.


Cooling system hose is collapsed, restricted, or leaking

Inspect the hoses. Refer to the OEM service manual.


Fan drive belt or water pump belt is loose

Check the belt tension and tighten if necessary. Refer to Procedure 008-002 (Drive Belt, Cooling Fan) in Section A.


Lubricating oil level is above or below specification

Check the oil level. Add or drain oil, if necessary. Refer to Procedure 007-043 (Lubricating Oil Level) in Section 3.


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 (Supplement Coolant Additive (SCA) and Antifreeze Concentration) in Section 5.

Contact a Cummins Authorized Repair Facility

Last Modified:  09-Dec-2004