Date: Mon, 24 Dec 2001 11:40:29 -0800
Reply-To: Doktor Tim <doktortim@ROCKISLAND.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Doktor Tim <doktortim@ROCKISLAND.COM>
Subject: Re: ongoing problems please help
In-Reply-To: <20011224174224.67128.qmail@web20005.mail.yahoo.com>
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At 09:42 AM 12/24/2001 -0800, you wrote:
>
>Hi Again,
>Just to recap and try to not bore you with all the details let me start
>by saying I have been back to the dealer six times trying to resolve
>the coolant system problem that is plaguing me...in the process I have
>a new H flange, new radiator, new radiator sensor, new fan switch, new
>coolant reservoir sensor, new battery, new switch and a new thermostat,
the system has been bledrepeatedly... Something is forcing the
>coolant back into the reservoir and then into the overflow tank.
So sad, as some of this cost would likely be apparent as unneccesary with
proper testing. Just how crusty had the cooling system become before all
these parts replacements???
Run it until the condition begins to present itself. Continue to monitor
until you see the obvious evidence of excess pressure.
Shut it down and do an immediate leak down test on each cylinder and the
pressure cap. Verify before you hire anyone that they possess a leakdown
guage set. It must have 2 guages, one to show delivery pressure and another
to show pressure drop. It will also have incorporated an air valve to set
the delivery pressure to 100 psi for direct percentage read-out of pressure
loss. With the pressure cap off you will see air bubbles coming out the
pressure tank if a head seal is the culprit.
Sounds like a head seal problem (almost/maybe/for sure) and the leak-down
test will prove it. If that's what it is, budget at least R&R heads. Reduce
risk by using new heads and nothing but the factory VW sealants/gaskets. If
there is any pitting or evidence of corrosion on the head studs, replace
them all. The source of this failure is many times a cracked stud from the
pits making stress risers happen. Know those pits can be very small, just
lying under that little piece of surface crust you see here and there.
Feel the inside of the tail pipe. If it is wet with anti-freeze it will be
slickery between the fingers. Quite different than just condensed water.
That would be empirical proof for a cylinder head leak.
This
>dealership is supposed to be good
All evidence to the contrary. Ask them about a leak-down test, and if they
have a guage set. I wonder if this dealership has any mechanics old enough
to have had experience with these motors. Some of the younger ones might be
proceeding without the benefit of getting out the Bentley and may be
totally unaware of the proper bleeding procedure. If the radiator remains
relatively cool during the overheating, it could well be an air lock
preventing flow, and just due to improper procedures. All I'm saying is,
you can assume because you take it to a dealer they will follow FACTORY
procedures, or you can verify they have the equipment, knowledge and skills
to make an accurate diagnosis prior to spending money on parts. However,
any component that shows the effects of coorosion is a candidate for
replacement, so there is value in new parts, but only if the source of the
problem is corrected as well.
T.P. Stephens
Doktor Tim's
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