V6 Oil pump.

[Tom Leppke-Hennig]

Hello,

Re: 1995 90Q, 109,000 mi (V6-12v, AFC code)

Let me share a story with everyone. I recently started experiencing low
oil pressure at idle, only when oil and water are at full operating
temperature. This particular car is equiped with an oil pressure gage,
but it was a flickering warning light that prompted me to look down at
the gage. It was basically pegged at zero at this time. The slightest
increase in RPM would yield an increase to a more reasonable level. Oil
pressure was lower than "normal", but still OK at freeway speed, so I was
able to get it home.

I verified the gage with a seperately installed mechanical gage. Low
pressure checks out. With my perusal of the archives, coupled with
inquiries at the dealership, I have decided to check out the oil pump as
a likely cause. So, I have begun the big tear-down. For those who do not
know, the oil pump on this motor is the ring-gear type that is concentric
to the front end of the crankshaft, integral to the front seal carrier. A
timing belt job was overdue on this motor, so that will obviously be
getting done as well.

Items of note: The service writer said they replace a fair amount of oil
pumps in the 12V-V6, both engine code AAH and AFC. Also, Carousel's
(Minneapolis dealership) price on the pump was in line with all the
online/telephone suppliers I checked out. (The stupid pump is 7 times the
cost of a VW 8V oil pump, of which I have never had or even ever heard of
having a failure. Progress, ya know.)

The project has been completed now, and the oil pressure is back to
normal. In spite of the expense in money and time, I am relieved. It took
all weekend plus a few weeknights after work to complete the project.
This isn't as bad as it sounds because I also got a complete flush of the
cooling system, an oil change and a timing belt change out of the deal.
Also, I spent more time cleaning the exterior of the motor than I would
have if it were just an in-and-out job.

Misc. items: Replaced many of the coolant hoses. Re-bearinged the
alternator and trued up the slip-rings, while I had it out on the bench.
Brushes still looked fine. Replaced ALL of the idler pulleys and
water-pump (always with a timing-belt), and the car idles quietly now.

Interesting results: The car has more low-end torque than before the job.
The only possible conclusion I can draw is that the cam-timing must have
been off. That is possible, because the cam-gears are not keyed to the
cam shafts (as you may know). By the way, I have no more fear of the
timing belt job. Once you are armed with the tools, it is a cake-walk.
One of the timing-belt idlers felt really ugly. Glad I got to it before
disaster struck.

Bad results: I have a check-engine light now. I have a VAG-COM from
RossTech on order, and will report on the results of that when I run it.
I probably knocked a vacuum hose off, or something.

Tom LH