ISC, ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9 Engines – Crankcase Gases (Blowby) Excessive

Symptom Tree  t027

This is symptom tree t027
Cause Correction

Crankcase ventilation system is plugged

Check and clean the crankcase breather and vent tube. Refer to Procedures 003-002 and 003-018.


Air compressor is malfunctioning

Isolate the air compressor by disconnecting the air inlet and outlet lines. Refer to Procedure 012-003. Check blowby. If blowby is within specifications, rebuild or replace the air compressor.


Exhaust or engine brake is malfunctioning

Check the exhaust or engine brake for correct operation. Refer to Procedure 020-004.


Turbocharger oil seal is leaking

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


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

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


Cylinder head valve guides are excessively worn

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


Cylinder liner, pistons, or piston rings are worn or damaged

Check the pistons, piston rings, and cylinder liner. Refer to Procedures 001-043 and 001-047. Check the pistons for correct part numbers. Refer to Control Parts List (CPL), Bulletin 3379133 or 4021327.

Last Modified:  29-Jul-2005