Coolant In Lube Oil; Coolant System Inspection - Navistar International DT 466 Diagnostic/Troubleshooting Manual

Coolant in Lube Oil

Symptom
When the crankcase lube oil is contaminated with
coolant, the oil will have a dark-gray or black sludgy
appearance. The crankcase may also be overfilled.
Cause
• Accessory leak (water cooled air compressor)
• Injector sleeve leak
• Cylinder head cup plug failure
• Crevice seal (liner O-ring)
• Cylinder head gasket leak
• Front cover gasket damage
• Front cover, cylinder head or crankcase porosity
Tools
• Radiator pressure testing kit
• Plastic surge tank cap adapter
• Cylinder head test plate
• Water supply housing pressure adapter
• Thermostat opening pressure adapter (cylinder
head)
• Straightedge
• Feeler gauge

Coolant System Inspection

Procedure
1. Check oil level to verify oil contamination
complaint.
• The presence of coolant in the oil will
generally give the oil a dark-gray or black
sludgy appearance.
• If coolant in the oil is not verified, an oil sample
can be taken for analysis.
2. When oil contamination is verified, plug in cylinder
block heater to warm coolant.
3. Is the engine equipped with an air compressor?
• If yes, do step 4.
• If no, do step 8.
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.
Figure 123 Air compressor oil drain-back hose
4. Remove air compressor oil drain-back hose from
the bottom of compressor.
5. Install radiator pressure
appropriate adapter.
WARNING: To avoid serious personal
injury, possible death and damage to the
engine:
• Always allow the engine to cool for 15
minutes.
• Wrap a thick cloth around the cap.
• Loosen cap slowly a quarter to half turn.
• Pause for a moment to avoid water or
steam scalding.
• Continue to turn the cap and remove.
• Never add cold coolant to a hot engine.
This can result in a cracked cylinder head
or crankcase.
• Never use water as a coolant substitute.
6. Pressurize the cooling system to 96 kPa (14 psi).
7. Look for coolant leaking from the air compressor
oil drain-back port.
• If coolant is leaking from air compressor,
repair or replace air compressor.
• If coolant is not leaking from the air
compressor oil drain-back port, do step 8.
8. Drain engine oil and remove the oil filter.
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tester with the