Date: Mon, 11 May 2009 21:10:34 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Thermostat soup: A comparison.
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Does it overheat at idle only? If so then the thermostat is not the problem.
If it was failing it would always over heat, especially at speed. You say
the radiator fan is working. Does that mean it is cycling on its own? If it
is turning on by itself that one more indication the t-stat is OK. When the
fan is running, does the return become noticeably cooler than the feed? The
radiator may be plugged or an internal baffle is cracked and the coolant is
not actually flowing through it.
Changing parts until it works is rarely effective. Another possibility is
that a prior water pump failure damaged the engine case and reduced capacity
at low speed is the result.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Robert Fisher
Sent: Monday, May 11, 2009 8:15 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Thermostat soup: A comparison.
Stock '87 GL overheats at idle, radiator fan works on both speeds but has
little/no effect. I got a new thermostat (FLAPS special) and pulled the old
one. I don't remember what brand the old one is but it was supposed to be a
good one and it is far beefier in construction; iirc I got it at the local
import parts place back when but they were closed so I got this new one. Old
one is maybe 7 yrs. old, but does not have a lot of miles/cycles on it.
In boiling water, the new one opens to about 3/8" fairly quickly and also
closes fairly quickly. The old one opens (to my surprise), but to a little
less than a 1/4", and takes its sweet time opening and closing. On the one
hand, I'm thinking I might run the new one for the meantime, get myself
another 'better' one and swap them out keeping the FLAPS thermostat for a
spare. On the other hand, the old one didn't really give me much for my
money. I normally keep a spare around; I don't know what happened to it,
hence the FLAPS piece.
I know there's widely varying quality in these things, sometimes even within
brands and I've found them dead out of the box, which is why I check them (I
don't recall seeing one that 'partially' worked, however). I've also seen
ppl argue for strictly OEM thermostats here on the list but I'm a long way
from any VW dealer.
Thoughts? Recommendations?
Cya,
Robert