Cummins ISX11.9 CM2250 – Service Manual Crankcase Gases (Blowby) Excessive

Turbocharger oil seal is leaking

Isolate the turbocharger to determine if the turbocharger seals are leaking. Refer to
Procedure 014-010 in Section 14.

Air compressor is malfunctioning

Isolate the air compressor by disconnecting the air inlet and outlet lines. Refer to the OEM service manual.

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.

Rocker lever housing gasket is leaking

Check the rocker lever housing gasket. Refer to
Procedure 003-011 in Section 3.

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

Check for air intake system leaks. Refer to Procedure 010-024 in Section 10. Check the pistons, piston rings, and liners for wear or damage. Refer to
Procedure 001-028,
Procedure 001-043, and
Procedure 001-047 in Section 1.