Cummins ISX11.9 CM2250 – Service Manual Lubricating Oil Consumption Excessive

Verify the oil consumption rate

Check the amount of oil added versus the mileage. Refer to .

Lubricating oil leak (external)

Inspect the engine for external oil leaks. Tighten the capscrews, pipe plugs, and fittings. Replace gaskets, if necessary. Refer to
Procedure 007-024 in Section 7
.

Crankcase ventilation system is plugged

Check and clean the crankcase breather and vent tube. Refer to
Procedure 003-001 in Section 3 .

Air compressor is pumping lubricating oil into the air system

Check the air lines for carbon buildup and lubricating oil. Refer to the Air Compressor is Pumping Excessive Lubricating Oil into the Air System symptom tree.

Lubricating oil dipstick calibration is not correct

Check the dipstick calibration. Refer to
Procedure 007-009 in Section 7
.

Lubricating oil drain interval is excessive

Verify the correct lubricating oil drain interval. Refer to Procedure 102-002 in Section 2 in the Operation and Maintenance Manual, ISX11.9 CM2250, Bulletin 2883444.

Lubricating oil does not meet specifications for operating conditions

Change the oil and filters. Refer to Procedure 007-013 and
Procedure 007-037 in Section 7. Refer to Cummins® Engine Oil and Oil Analysis Recommendations, Bulletin 3810340 . Use the oil type recommended in Section V.

Turbocharger oil seal is leaking

Check the turbocharger compressor and turbine seals. Refer to
Procedure 010-033 in Section 10
.

Lubricating oil cooler is leaking

Check for lubricating oil in the coolant. Refer to the Lubricating or Transmission Oil in the Coolant symptom tree.

Lubricating oil is contaminated with coolant or fuel

Refer to the Lubricating Oil Contaminated symptom tree.

Valve stem clearance is excessive or the valve stem seals are damaged

Check the valve stems and seals. Refer to
Procedure 002-004 in Section 2
.

Cylinder head valve guides are excessively worn

Check the valve guides for wear. Replace the cylinder head if necessary. Refer to
Procedure 002-004 in Section 2
.

Piston rings are not seated correctly (after an engine rebuild or piston installation)

Check blowby. Refer to Section 14. If blowby is excessive, check the piston rings for correct seating. Refer to Procedure 001-043 and
Procedure 001-047 in Section 1.

Piston, cylinder liner, or piston rings are worn or damaged

Check for air intake system leaks. Refer to Procedure 001-043,
Procedure 001-047, and
Procedure 001-028 in Section 1.

Injector o-rings are damaged or missing

Remove and check the injectors. Replace the injector o-rings. Refer to
Procedure 006-026 in Section 6
..