I'll give it a go. First with the compressed air, then the stud check,
then pulling a head. Hopefully by then I'll know which way to go from
there. Thank you both for answers and advice.

Walter

On Sat, 26 Jan 2013 19:38:47 -0800, Scott Daniel - Turbovans
<scottdaniel@TURBOVANS.COM> wrote:

>worth a try.
>Might mention that coolant will come out if head nuts are loosened (
>drain coolant first )
>and that each nut needs to be resealed ..
>as they seal in coolant.
>
>S.,
>On 1/26/2013 7:02 PM, Dennis Haynes wrote:
>> You definitely need to do some testing to try to determine why the
>> compression is down on those two cylinders. Before pulling the heads I
would
>> check the torque on the head nuts. Internal leaks between the tops of
the
>> cylinders and heads are really due to failure of the studs to keep the
heads
>> down under those compressive/pressure loads and the temperature changes
of
>> the engine parts. I have repaired a number of internal leak issues by
>> re-torqueing the heads. The other failure point is cracked heads
allowing
>> the gasses into the cooling system. Coolant-hydrocarbon testing is not
>> always effective for diagnosing. As part of the leak down test, by pass
the
>> gauge and apply full shop air pressure to the cylinders (secure the
>> crankshaft securely) may make the leak obvious.
>>
>> Dennis
>>
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of
>> Walter Houle
>> Sent: Saturday, January 26, 2013 8:08 PM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Coolant Overpressurization / Head Gasket Leak
>>
>> The morning after the 300 mile drive home from BBB I noticed that the
>> coolant overfolw tank was full and overflowing a few drips. The
expansion
>> tank was also 100% full. I opened the pressure cap a little bit at a
time
>> and a lot of coolant pushed out - this on a stone cold engine that was
>> sitting for 12 hours. It looks like I have an internal head gasket leak.
>> The strange part was that the van ran strong all the way home and didn't
>> show any obvious signs of overheating. We stopped and checked it twice
along
>> the way, no drips, no smell, and no excess heat. The temp gauge was
over the
>> right edge of LED and it behaved normally, up a tad on the climbs, and
down
>> a tad on the descents, just like always. I did a compression test today
and
>> it was 170-170-140-150. Its been low on 3 & 4 like that for a while,
last
>> test was 6 months ago, but this is the first time I've had coolant
issues.
>> I will try a hydrocarbon sniff of the coolant and then a leakdown test
to
>> confirm. I've read a lot in the archives, and its looking more and more
like
>> its a compression leak, and it looks like it is only occuring under
load.
>> The heads are old and have never been off, original VW factory rebuild,
15
>> years and 75K miles ago.
>> Yes, this is way overdue and I should have taken care of this earlier.
>>
>> I am assumming new heads are in order, and I'm hoping that is going to
be
>> it. What about the rest of the engine? If it was pushing coolant away
from
>> the cylinders, it was doing it for a long period of time. WHat else
should I
>> be looking at?
>>
>> Thanks,
>> Walter
>> 1985 Vanagon 1.9 in San Diego
>>