low compression--update

[amalventano@sc.rr.com (Allyn)]

Mike,
there are multiple layers to piston rings. it would be a very tough call
without pulling that piston. also, if a ring did go, it probably
cracked/snapped/otherwise broke, which usually leaves tell-tale signs on the
cylinder wall. did you roll the crank and check out the wall of #4?
Al

----- Original Message -----
From: "Michael Abatzis" <abatzis2@hotmail.com>
To: <scirocco-l@scirocco.org>
Sent: Saturday, February 22, 2003 6:52 PM
Subject: low compression--update


> in an effort to find low compression in my #4 cylinder, i did a leakdown
> test; heard a leak in the intake manifold (strangely, it was heard best in
> the #1 pipe). pulled the head. found nothing. lost a head stud washer, so
i
> can't clamp it back down till tomorrow, but since i didn't do anything but
> clean a bit, i can't imagine i fixed anything. i'm kind of at a loss
> now--would anything that causes a 120 psi (210 vs. 90) difference b/t
> cylinders be obvious? i would think it would. the differential:
>
> head gasket/warped head: i doubt it. the 3 other cylinders were within
spec,
> and there has been no coolant loss/mixing. HG looked ok, but it's tough to
> tell cause it's metal.
> broken ring: ?? everything looked ok from the outside, but i'm not sure
what
> to look for.
> intake/exhaust valve leak: that's what i'd suspect, but both seemed to
seat
> pretty good. didn't see anything that would suggest they were bent.
>
> anything else? here are some pix:
>
>
http://www.learnlink.emory.edu/~mabatzi/head%20work/head%20removal%20001.jpg
>   --this is right after taking head off
>
http://www.learnlink.emory.edu/~mabatzi/head%20work/head%20removal%20002.jpg
>   --close up of #4 piston.
>
http://www.learnlink.emory.edu/~mabatzi/head%20work/head%20removal%20003.jpg
>   --cylinder head
>
http://www.learnlink.emory.edu/~mabatzi/head%20work/head%20removal%20004.jpg
>   --#4 intake valves
>
http://www.learnlink.emory.edu/~mabatzi/head%20work/head%20removal%20005.jpg
>   --valves closed on #4
>
>
>
>
> -Michael Abatzis
> Hotlanta! GA
> 1988 Scirocco 2L 16v RIP-->parting, finally taking orders:
> www.learnlink.emory.edu/~mabatzi/mikes_page1.html
> 1987 Scirocco 2L 16v...
>
>
>
>
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