M11 – Lubricating Oil Sludge in the Crankcase Excessive

Symptom Tree  

Bulk oil supply is contaminated

Check the bulk oil supply. Drain the oil and replace with noncontaminated oil. Replace the oil filter(s).


Lubricating oil does not meet specifications for operating conditions

Change the oil and filters. Refer to Procedure 007-013 (Lubricating Oil Filters – Spin-on) in Section 4. Use the oil type recommended in Section V.


Lubricating oil drain interval is excessive

Verify the correct lubricating oil drain interval. Refer to Procedure 102-002 (Maintenance Schedule) in Section 2.


Fuel grade is not correct for the application or the fuel quality is poor

Operate the engine from a tank of high-quality fuel. Refer to Procedure 018-002 (Fuel Recommendations and Specifications) in Section V.


Lubricating oil is contaminated with coolant

Check the lubricating oil for coolant. Refer to the Coolant Loss – Internal symptom tree.


Crankcase ventilation system is plugged

Check and clean the crankcase breather and vent tube. Refer to Procedure 003-018 (Crankcase Breather Tube) in Section 3.

Contact a Cummins Authorized Repair Facility

Last Modified:  09-Dec-2004