MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
116
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
The seal of turbocharger is achieved by the higher air pressure established in the housings at both ends
of the turbocharger than the air pressure in the intermediate body fuel return chamber (equal to the air
pressure in the crankcase).
Before diagnosis, make sure there is no malfunction such as engine oil in the pipe before the gas
compressor housing intake port, oil pollution in the exhaust pipe before turbine housing intake port, etc.
Malfunction diagnosis for oil leakage at
the compressor:
①
Check whether the compressor
impeller is broken by foreign
matters
②
Check whether the axial/radial
clearance
of
turbocharger
is
largened (whether the compressor
blade has interference with its
housing)
Clean and repair the air intake
system or replace the turbocharger
Eliminate the factors that largen the
turbocharger clearance or replace
the turbocharger
Clean the lubricating oil and avoid
long time idling
③
Check whether the idle speed
time of engine is too long (more
than 20 min)
⑤
Check whether the turbocharger
air intake pipe is throttled
Tighten the pipe or replace the
broken pipe
⑦
Check whether the lubricating
oil return hose of turbocharger is
blocked
Eliminate the factors that throttle
the turbocharger air intake pipe
Clean it and clear the throttling
factor. Replace the lubricating oil
and the oil return hose if necessary
⑧
Check whether the engine
crankcase respirator is blocked
See the maintenance manual of
engine manufacturer for check and
repair
⑨
Check
whether there is
malfunction in the engine (serious
blow-by of piston or overhigh
pressure in the crankcase)
See the maintenance manual of
engine manufacturer for check and
repair
⑩
Check whether there is too
much
lubricating
oil
in
the
crankcase
Adjust the oil in the crankcase to a
proper level
It is advised to measure the air intake pressure (reference value:
≤
6.5 kPa)
Replace the filter core of air cleaner
④
Check whether the air cleaner is
too dirty
⑥
Check
whether there is
looseness or breakage in the air
intake/exhaust pipe
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
