[s-cars] RE: S-CAR-List digest, Vol 1 #1803 - 11 msgs

[Kaklikian, Gary]

I don't have this problem with my S4 since it's relatively stock. But it is a common problem with modified 944 turbos - blowby, excessive crankcase pressure, oil in the intake.  I experimented with routing my crankcase vent hose to a catch can instead of the turbo inlet as you say, but then the dipstick would blow out on the track (running "only" 16psi). Others have lost cam seals doing this (on 944 turbos).  Yes, oil in the combustion chamber is not a good thing, but the venturi effect of the turbo inlet helps relieve the crankcase pressure. Of course, if your rings were sealing perfectly and you were running "normal" boost levels, then the catch can would probably be fine, but then no oil would collect anyway.

Funny thing is when I installed a catch can, no oil was collected either. Seems like most of it is getting by the seals on my new Garrett turbo (a common problem with Garrett's, again at least on 944 turbos.) The vendor says the problem is not the turbo, but the piston rings.  And recommended against placing a restrictor in the oil feed line, as is commonly done with Garrett's on 930's.

And if it's any consolation, my 944 turbo used 2 quarts of oil in 3 30-minute track sessions today, yet ran like stink with little smoke visible?!



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Message: 8
Date: Fri, 12 Sep 2003 14:01:57 -0700 (PDT)
From: brian bilotti <vinnieb2 at yahoo.com>
To: s-car-audi-kruemmer <audi20v_kruemmer at yahoogroups.com>,
	s-car-list at audifans.com
Subject: [s-cars] was: NEW MOTOR-Oil in breather system- UPDATE

Ladies and Gentlemen,
Specifically Mark Halligan, Jani Peltopuro, Tommy
Arnberg, and the rest of you gearheads, you know who
you are. Here's an update, it seems that this oil in
the breather system issue is shared by several others
and I suspect that everyone has this issue but it is
excasperated by higher horsepower/boost pressures. As
most of you know, I have been driving around with a
clear, vented bottle with a hose attached to the front
of my valve cover (replacing the valve cover to turbo
hose). While driving with a full crankcase (top of
hash marks)this bottle would partially fill, 1/4 of a
quart. This would occur only under boost conditions.
At the same time I monitored the oil level on the
dipstick and once it got to half way on the hash
marks, NO MORE OIL went in the bottle. Nada, zip,
zilch. Hmmm, it has been suggested that I might have
the wrong dipstick or the dipstick tube was elevated
somehow, NOPE. I checked both with a friends S4. Soo,
it seems the next step is to add a breather bottle and
eliminate any chance of oil going through the intake
system.
My recommendation to anyone running higher boost is to
check your intake hose coming from your IC and going
to your throttle body and see if there's an oil film
in there. If so, you're pumping oil into your
combustion chambers and we all know that's not a good
thing. I welcome anymore comments or advice.

May the rings be with you

Brian

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