What really does cause induction contamination? - TAT - The ...

YOU
SAID
IT!
Oil and water just don’t
mix in a VW Transporter
Vehicle: VW Transporter
Engine: AXE/TDI
Kilometres: 117,358
Transmission: manual 6
speed
The vehicle was losing water
into the crank case, with no
sign of overheating.
We first investigated the
engine oil cooler because there
were no visible leaks and no
discernable drop in pressure.
The vehicle was then driven for
about 45 minutes before the
coolant low light came on.
The air conditioning
compressor was removed
to gain access to oil filter
housing.
 
The engine oil cooler
is bolted onto the oil filter
housing via five torx screw and
four o-rings to seal between oil
and water.
The oil filter housing is bolted
onto the engine block via a
metal gasket. Water is fed by
an external hose through the
cooler and then back into the
block – so only one hose.
You cannot bypass the oil
cooler to test and it would have
been too hard with the a/c
compressor in the way.
The oil cooler, o-rings and
gasket were replaced.
Watermarks could be seen
bypassing the o-ring into the
oil, so we thought we had hit
the nail on the head.
 
After
flushing the oil and cooling
system, it pressure tested OK.
Drove the car for about 45
minutes and the coolant level
low warning appeared on the
dash. Back in the workshop,
there was water in the oil.
Now we were scratching our
heads.
 On further diagnosis
we found that the water pump
is gear driven and is inside the
rear of the engine block. The
inspection plate was removed
and we found the water pump
bearings collapsed.
Also, because of free play
on the water pump shaft, the
gear drive had been hitting the
securing bolts and shaved half
of the head away. Luckily we
managed to get them off with a
bit of a struggle.
So for anyone getting a
water-in-oil problem with this
engine, with no evidence of
external leaks and the car
not overheating, replace the
engine oil cooler and water
pump at the same time.
Don’t forget to order water
pump bolts and receiver drier
for the a/c.
Parts list:
VW-070121011DX
Water pump
VW-N91046902
Water pump screws
(stretch bolts by the way)
VW-071115562C
Oil filter 
VW-070117021D
Oil cooler VCP 17C6 13
VW-070198389
Seals VCP 17C6 1328 (comes
with four o-rings)
VW-070115441A
Gasket, oil filter HSG
VW-
7L0898191A
Drier, air conditioning
 oil
flush, coolant flush, coolant
and oil.
Total time taken over 8 hours
including oil and coolant flush,
but can probably do it in 4-5
next time without messing
around.
Hope this helps a fellow
technician.
Bruce Yeung
Autoactive Car Solutions
ARTARMON NSW
Remove the a/c compressor
Oil cooler and oil filter housing
Worn water pump bolt heads
inside the rear of the motor
Water in the oil on the filter
Worn and damaged water pump
Note the corrosion around the
o-ring marks on the oil cooler
mounting
Water pump mounted at the
rear of the motor
The Automotive Technician 23