4 ENGIN E SY M PTOMS DIAGNOSTICS 117
Coolant Leak to Exhaust
Symptom
• Coolant residue at exhaust manifold flanges
• Observation of coolant loss without engine
overheating
• Excessive white smoke from exhaust pipe on start
up (hot or cold)
• Coolant smell in exhaust
• Coolant leaking from m u ffler
• Severe case – engine hydraulic lock
Cause
• Failed EGR cooler
• Injector cup and gasket leak
• Intake side o f cylinder head cup plugs leaking
• Porosity in c ylinder head casting
Tools
• Regulated compressed air
• Water supply housing pressure adapter
• Radiator pressure testing kit and plastic surge cap
adapter
• EGR cooler pressure test plates (2)
Procedure
Figure 133 EGR cooler without cross-over tube
1. Remove EGR crosso ve r tube as sembly following
the proce dure in the Engine Service Manual.
2. Check for presence of coolant in EGR cooler and
tube.
3. Plug in the cylinder block heater to warm coolant.
4. Install radiator pressure tes ter with the
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.
5. Pressurize cooling systemto96kPa(14psi).
6. Check EGR cooler for the presence of coolant.
• If coolant is present, replace EGR cooler
following the procedure in the Engine Service
Manual.
• Ifnoleakisfound,dostep7.
If pressure is dropping rapidly, coolant may be
leaking from the EGR cooler into the exhaust
manifold or tail pipe.
7. Drain co olant from the system.
8. Remove EGR co o ler f ollo win g t he procedure in
the Engine Service Manual.
EGES-270-1
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
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