Date: Mon, 6 Aug 2001 11:26:09 -0400
Reply-To: Paul Cavanaugh <phonyexpress@IWAYNET.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Paul Cavanaugh <phonyexpress@IWAYNET.NET>
Subject: Re: pressure in cooling system
In-Reply-To: <a05010401b7927f9ba364@[24.12.219.103]>
Content-Type: text/plain; charset="us-ascii" ; format="flowed"
Hi John,
Thanks for writing. It is possible that the transmission coolers blew
from a separate problem - maybe an overheating/pressurized
transmission? I know nothing about trannys, except that this is the
first problem I have had with one in 25 years of VWs - spread over 4
vehicles and 600,000 miles.
I've had two shops look at the car - one says the hoses "feel" over
pressured, though I would think that would blow the pressure cap on
the expansion tank. They can't seem to do a good pressure test or a
coolant test for exhaust. Their recommendation, from experience, is a
rebuild.
My main shop says no excessive pressure is showing at this time
(intermittent?) and no hydrocarbons showed up in the coolant test. He
is not sure what is going on.
Neither shop seems to want to do a compression test, though I have
suggested they pressurize the cylinders over night.
I may take it to a third place.
I would feel better about rebuilding the engine if I was sure of what
was going wrong. Already had the tranny rebuilt when the 2nd cooler
burst.
Paul
>Very nice vanagon pictures, and impressive mileages! I'm not sure
>why a transmission cooler would blow from excessive cooling system
>pressure. High cooling system pressures can also cause damage to
>the plastic tanks in the engine compartment-check those tanks. Feel
>the hoses while the engine is running. I thinkk blown gaskets
>should also be detectable with a compression tester. Have you any
>traces of oil in the coolant, or coolant in the oil sump?
>
>At 188,000 miles, I would opt for the complete rebuild.
>
>John Hung
>'84 GL
>150,000 miles
>Auburn, AL
>
>>Date: Sat, 4 Aug 2001 13:19:06 -0400
>>From: Paul Cavanaugh <phonyexpress@IWAYNET.NET>
>>Subject: Help! Am I doing this right????
>>
>>I have a '90 that has been blowing cooling system parts (Transmission
>>coolers, rear heater cores, etc.) The general feeling is that
>>compression from the cylinders is leaking into the cooling system,
>>causing excessive pressure.
>>
>>I pulled the spark plugs to look for the offending cylinder. The
>>picture on my web site shows the four plugs:
>>
>>http://www.phonyexpress.com/images/sparkplugs.jpg
>>
>>The ceramic on Number 2 (at the far right in the picture) spark plug
>>is very clean compared to the brown look of the others, while there
>>is a lot of buildup on the metal (brownish white), which might
>>suggest corrosion from the moisture here, while the clean ceramic
>>comes from coolant in the cylinder. Am I reading this right????
>>
>>The car has 188,000 miles. Even if it is just one cylinder creating
>>the pressure problem, would everyone concur that a complete rebuild
>>is the way to go vs. just fixing the one cylinder?
>>
>>Thanks for your advice!
>>
>>Paul In Columbus, Ohio
>>
>>Pictures of my Vanagons:
>>
>>http://www.phonyexpress.com/images/VWs.jpg
>>--
>>'90 Vanagon (180k)
>>'84 Vanagon (217k)
>>'78 Microbus (175k)
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