I just talked to a VW mechanic today about a vanagon he was working on in
his shop.  He uses a plug that has the same threads as a spark plug with a
schraeder valve attachment on it.  He then fits the  plug into the
individual cylinder spark plug hole and applies about 60psi while watching
the expansion tank for bubbling.  This is how he was able to identify the
precise cylinder sleeve and head gasket that was leaking.  I saw the parts
he later pulled out of the motor after testing and they were indeed hosed.
So to answer your question, yes that is a valid test to get a rough idea of
head gasket condition.  Further testing to isolate which side would probably
use the method I just described.

Rich Blake

Date:    Fri, 27 Sep 2002 08:27:53 -0700
From:    kevin obrien <kevindobrien@YAHOO.COM>
Subject: Test for Bad Head Gasket....Please advise.

Hello All:

Anyone following my threads about my 1990 Carat
overheating uphill knows I've been trying to figure
this out for awhile. I took her to a guy this morning
that said he had a simple test...he removed the
Expansion Tank cap...pulled the coil off the rotor and
had his assistant turn the engine over.  Bubbles could
be seen in the Expansion Tank as the engine cranked.
He says that's a sure sign...bad Head Gaskets or
cracked head.

Is he correct? Any and all input appreciated.

Thanks!
kevindobrien@yahoo.com