Fuel In Lube Oil - Navistar International DT 466 Diagnostic/Troubleshooting Manual

124

Fuel in Lube Oil

Symptom
Oil contaminated with diesel fuel will cause the oil level
in engine to increase.
Cause
• Leaking fuel injector or injector O-ring (A leaking
injector sleeve or injector tip could cause
contaminated engine oil, but would most likely be
identified as a performance problem.)
• Cracked or porous cylinder head casting in fuel
rail area cross-drillings
Tools
• 2 oz of fuel dye
• UV Leak Detection Kit (black light)
• Fuel pressure gauge kit
• Fuel pressure test adapter
• Fuel/Oil Pressure Test Coupler
• 1 to 5 gallon bucket
• Inspection mirror
Procedure
NOTE: The black light requires warm-up time. Turn
on the black light
1. Verify oil contamination.
NOTE: Other issues that may contribute to fuel
dilution beside fuel injectors, include the following:
• Hard starting
• Running rich (strong fuel odor)
• Valve related issue
If the engine is mechanically sound and the oil
has been changed, diagnose for fuel in the oil with
dye.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
4 ENGINE SYMPTOMS DIAGNOSTICS
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
2. Remove the fuel filter housing cap.
NOTE: If the fuel filter housing cap is out of the
system for an extended time, the O-ring will swell
and needs to be replaced.
3. Add 2 oz fuel dye to the fuel filter housing.
NOTE: Use only
manufactured by Balkamp,
at local NAPA Auto Parts stores, part number
765-2661.
4. Install the fuel filter housing cap.
CAUTION: Be sure to place a rag or suitable container
under the fuel pressure test valve when bleeding the
fuel rail. Dispose of fuel in a correct container clearly
marked DIESEL FUEL according to local regulations.
NOTE: Engine fuel can be a threat to the environment.
Never dispose of engine fuel by putting it in the trash,
pouring on the ground, in the sewers, in streams, or
bodies of water.
Figure 143 Shrader valve assembly
1. Valve
2. Center stem
recommended dye,
Inc., available