Electronic Control System Signature, ISX and QSX15 Engines – Fuel in the Lubricating Oil

Symptom Tree  t092

This is symptom tree t092
Cause Correction

Bulk oil supply is contaminated

Check the bulk oil supply. Drain the oil and replace with noncontaminated oil. Replace the oil filter(s). Refer to Procedure 007-025 and 007-013 in the Troubleshooting and Repair Manual, Signature, ISX and QSX15 Engines, Bulletin 3666239.

 

Engine idle time is excessive

Low oil and coolant temperatures can be caused by long idle time (greater than 10 minutes). Shut off the engine rather than idle for long periods. If idle time is necessary, raise the idle speed. Procedure 007-025 and 007-013 in the Troubleshooting and Repair Manual, Signature, ISX and QSX15 Engines, Bulletin 3666239

 

Fuel pump seal is leaking

Confirm fuel seal leakage at the fuel pump wheep hole. Refer to Procedure 005-016 in the Troubleshooting and Repair Manual, Signature, ISX and QSX15 Engines, Bulletin 3666239.

 

Top injector o-ring or injector timing plunger is damaged

Perform the fluorescent dye tracer test to find the bad injector. Replace the injector or o-ring. Refer to Procedure 006-026 in the Troubleshooting and Repair Manual, Signature, ISX and QSX15 Engines, Bulletin 3666239.

 

Fuel drain line restriction

Check the fuel drain lines for restriction. Refer to Procedure 006-012 in the Troubleshooting and Repair Manual, Signature, ISX and QSX15 Engines, Bulletin 3666239.

 

Injector is malfunctioning

Perform the cylinder performance test. Replace injectors as necessary. Refer to Procedure 006-026 or 014-008 in the Troubleshooting and Repair Manual, Signature, ISX and QSX15 Engines, Bulletin 3666239.

 

Cylinder head is cracked or porous

Remove intake and exhaust manifolds. Check for evidence of coolant leak. If necessary, operate engine at low idle. Pressure-test the cylinder head. Refer to Procedure 002-004 in the Troubleshooting and Repair Manual, Signature, ISX and QSX15 Engines, Bulletin 3666239.

 

Base engine problem

Check the engine for high crankcase pressure, low compression, static injection timing, damaged pistons, camshaft, and other parts. Procedure 002-004 in the Troubleshooting and Repair Manual, Signature, ISX and QSX15 Engines, Bulletin 3666239

 
Last Modified:  11-Dec-2003