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Re: #5 cyl. I-5 typically has a problem=clogged exhaust manifold?


    No.5 cylinder tends to run hotter than the others on the I-5 engine.
With that much carbon in the exhaust port, you were probably burning oil in
that cylinder. No.5 may have overheated and cooked the oil control ring to
the point where it lost it's spring tension.

Fred Munro
'91 200q  260k km
-----Original Message-----
From: Nathan Belo <belo@eskimo.com>
To: Quattro List <QUATTRO@coimbra.ans.net>; northwest audi enthusiasts
Date: Tuesday, October 13, 1998 7:15 PM
Subject: #5 cyl. I-5 typically has a problem=clogged exhaust manifold?

>Car:  1988 90Q tornado red, NG = no good ;) engine
>Mileage: 181K+
>Problem: No compression #5 and burning oil
>Solution: Pull head and bring to machine shop for hot tank, valve job,
>head surfaced, etc.
>Condition of head: All valve guides evenly loose, no broken/bent valves,
>no burnt exhaust/intake valves.  ***Exhaust manifold #5 is supposed to be
>about a 1.25-1.5" diamater, but it was so coked up with carbon there was
>barely a 1" dia. hole***  3 hairline cracks between valves that didn't
>seep into the valve seats.  Machine shop said this is common with the
>aluminum heads and not too worry unless it was seeping down into the valve
>seats.  For an additional $200 they could weld the cracks and put in new
>valve seats.  We're just bolting it back on.
>Hungarian VW factory trained mechanic for 30 years (Rabbit Service on Lake
>City Way in Seattle) says the pistons are fine.
>I heard a rumor that the #5 cylinder typically doesn't get enough air and
>runs lean.  Is this true and would that explain the clogged exhaust
>Nathan Belo
>'88 90Q