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From: pwv@fluke.UUCP (Pat Vilbrandt)
Newsgroups: net.auto
Subject: Re: 3.8l V6 GM Engine Using Oil
Message-ID: <1142@vax1.fluke.UUCP>
Date: Thu, 29-Aug-85 17:03:33 EDT
Article-I.D.: vax1.1142
Posted: Thu Aug 29 17:03:33 1985
Date-Received: Sat, 31-Aug-85 07:33:47 EDT
References: <2769@harpo.UUCP>
Distribution: net
Organization: John Fluke Mfg. Co., Inc., Everett, WA
Lines: 49
Keywords: Mobil 1, Burning Oil, net.auto.tech!!!

Irv McNair writes:

> I have a 1979 Buick Century Wagon witha 3.8l V 6 engine.
> It is burning oil at the rate of 1 quart per 400 to 600
> miles.
   .
   .
> The oil I am using is Mobil 1.

I strongly recommend that you get a compression check done on your engine.

I recall talking to a friend who was a mechanic for a Pontiac dealership in
'78 as he was busily rebuilding a new V6 engine (same or very similar to 
yours) that had very badly scored cylinder walls.  He was grumbling that the
owner had used Mobil 1 which, at 5W-20 weight (then) was too thin to protect
the cylinders on the V6 *at maximum operating temperature*.  Seems these 
engines were designed to operate *very* hot (coolant temperatures of up to
260 'F, I believe) for emission control.  It didn't take much for these 
engines to really overheat (eg. stuck in freeway traffic on a hot day).  

If the compression in one or more of the cylinders is significantly low, it
could indicate that the above has happened.

This is one of the reasons that Mobil changed Mobil 1 to 5W-30 weight (and 
more recently 5W-40, I believe).

Sorry for the pessimistic prediction, but past experience supports it.  With
badly worn cylinders and/or rings, oil consumption will be worst when the
engine is cold and will improve as the engine warms up and the parts expand.
This could explain why the oil consumption is less on long drives.

				Good Luck!

As a side; This kind of discussion is what I read net.auto for.  I am also 
about ready to unsubscribe to net.auto.(seatbelts,DWI,insurance,radar,crap}.
Add my vote for net.auto.tech!!!!!

Disclaimer:  I like Mobil 1.  I use it in my Subaru (100K+ miles).  I just 
wouldn't own any GM iron.  I have no (money) interest in either Mobil or GM.

-- 

   Pat Vilbrandt
   John Fluke Mfg. Co., Inc.
   Everett, Washington USA
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