[V8] Low compression - Baffled

[Andrew Schlueter]

If you can get it to idle, pull a vaccum line and stick it into a can of
seafoam. Use entire bottle. Let it sit for 5 min withy engine at
idle(white smoke can come out tail pipe at this time, its fine). Got
drive it, and come back at let it idle 5 more min and your good to go. I
just did with my v8 today. I had low compression on a cylinder, did a
leak down test, air coming out tail pipe. Seafoam cleaned the valve up
and made my v8 much much smoother.

Andrew W. Schlueter
'90 V8 MQuattro
www.westmotorsports.biz

-----Original Message-----
From: v8-bounces at audifans.com [mailto:v8-bounces at audifans.com] On Behalf
Of Tony and Lillie
Sent: Saturday, February 17, 2007 7:19 PM
To: V8 Audi Fans
Subject: [V8] Low compression - Baffled

Fellow V8 Audifans, 

I may have come to the end of the V8. I'm completely baffled, and I'm no
stranger to these car. 

I have a 1991 V8 with 325 K miles, in pretty good condition. It's an
auto car.

It ran great up until about two months ago. It's an occasional driver,
so sometimes it will sit for two weeks or so. Anyhow, after sitting
about two weeks, it wouldn't start. I drove the 4kq and let it sit for a
while. I've been poking at it on and off, but now my 4k got wrecked (I'm
OK, but I'm still dealing with the ins), I have decided to try to get
this car running again. 

Of course, right off I noticed that the car was turning over too fast
and not evenly (low compression in one or more cylinders), so the first
thing I did was to check the valve timing. I did the TB about 15k ago,
so right away I assumed I screwed up the tensioner or something. Well,
not the case. I've checked the timing with the mark on the pulley, and
the dots on the chain sprockets, Dead on. Oh, and I verified the Crank
mark with as being TDC for # 1, as that was another thing I recently
dealt with on the 4k. 

So, I did a compression test, and here are the results :(  Keep in mind
that this is a cold engine not run in about 2 months. I use the five
pump method when and engine is cold, using a remote starter switch.

#1: 120 psi
#2: 120 psi
#3: 40psi
#4: 45 psi
#5: 50psi
#6: 15 psi
#7: 90 psi
#8: 60 psi

The funny thing is, If they were all down I could look ofr an intake or
exhaust restriction. But, with them not even, I don't know what
happened. And, it was rather sudden, as the car ran great before. I
drive it hard (5000 RPM or more each shift till at speed) and would
notice one or two cylinders down. I would also suspect this negates the
chance for carbon to build up :) 

So, anyone out there have any ideas for me? 

The car does have oil in it, coolant is full. I do have spark and fuel,
these were the first things I checked for.

Tony Hoffman
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