PowerTech 6105HF - Check for Excessive Engine Crankcase Pressure (Blow-By)

Observable Diagnostics and Tests
04
150
12
DPSG,RG40854,282 –19–10AUG99–1/2
Check for Excessive Engine Crankcase Pressure (Blow-By)
RG10428 –UN–30NOV99
Breather Tube
A—Breather Tube
Excessive blow-by coming out of the crankcase
breather tube (A) indicates that either the turbocharger
seals are faulty or the piston rings and cylinder liners
are not adequately sealing off the combustion
chamber. This is a comparative check that requires
some experience to determine when blow-by is
excessive.
Run engine at high idle and check crankcase breather
tube. Look for significant fumes and/or dripping oil
coming out of the breather tube at fast idle, with no
load.
If excessive blow-by is observed, perform the following
to determine if the turbocharger is causing the blow-by:
1. Remove the turbocharger oil drain line where it
connects to the engine block and run the line into a
bucket.
2. Run engine at high idle, slightly loaded and
determine if boost pressure is forcing oil through
the drain line, and check crankcase breather tube
to determine if blow-by has decreased.
CTM100 (06APR04) 04-150-12 P OWER T ECH 10.5 L & 12.5 L Diesel Engines
040604
PN=360
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