Navistar International DT 466 Diagnostic/Troubleshooting Manual page 261

WARNING: To avoid serious personal injury,
possible death or damage to the engine or vehicle
– comply with the following:
When running the engine in the service bay, make
sure the parking brake is set, the transmission is
in neutral, and the wheels are blocked.
8. Run engine to reach normal engine operating
70 °C (158 °F) or higher, before measuring
crankcase pressure.
9. Run engine at high idle (no load) rpm. Allow the
gauge reading to stabilize before taking pressure
reading.
10. Record crankcase pressure on Diagnostic Form.
• If pressure is below specification, continue
Performance Diagnostics.
• If pressure is above specification, continue
with step 10.
Figure 335 Discharge port
11. If engine has an air compressor,
discharge air line and retest.
• If pressure is below specification, repair or
replace air compressor.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
6 PERFORMANCE DIAGNOSTICS
12. Disconnect VGT control module and retest.
13. Do Test 12 Relative Compression Test to pin point
14. Do Test 11 Injector Disable to further pin point
15. Inspect air induction for dirt ingestion.
Possible Causes
High oil consumption and excessive crankcase
pressure may indicate the following:
•
•
•
•
•
•
•
Low oil consumption and excessive crankcase
pressure may indicate the following:
•
•
remove
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
• If pressure is above specification, continue
with step 11.
• If pressure is below specification, reconnect
the VGT control module, and retest doing
Test 13 (Air Management) to see if crankcase
pressure increases as turbocharger demand
increases.
If pressure fluctuates above and below
specification, as the VGT is cycling, replace
the turbocharger.
• If disconnecting or cycling the turbocharger
does not bring pressure below specification,
continue with step 12.
suspect cylinders.
suspect cylinders.
Dirt in air induction system
Badly worn or broken rings
Cylinder sleeves badly worn or scored
Leaking valve seals or worn valve guides
A restricted orifice in crankcase pressure test
adapter
Failed turbocharger
Failed air compressor
Air compressor affecting crankcase pressure.
A restricted orifice in crankcase pressure test
adapter
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