Date:         Mon, 30 Jun 1997 13:15:33 -0400
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         kelphoto@bright.net (mark keller)
Subject:      Re:wasserboxer overheating/ impeller effeciency 

My suggestion if you have no visable leaks, but are experiencing cooling
problems is to have  a pressure check done.


The problem occurs because the waterpump impeller will not create enough
flow velocity, with a cooling system that does not have a good pressure
build up.  The most recent thread I saw, and a very good one I might add,
put the system pressures at 7lbs to 10lbs.  You should double check these
values.

A pressure leak could be anwhere, the common spots are the primary plastic
tank in the engine compartment, and the two heater control valves, You may
have only the one, above the spare tire.  Number two is under the rear seat
and beneath the center black heater core cover. A note there are several
other connectors, all should visable be checked.

I have read a various cooling system bugs, and wonder if this lack of
building system pressure and thus poor circulation is not to blame.  In
other words only one tank, the "overflow recovery tank", that is accessable
from the liscense plate opening, has atomspheric pressure.  The rest of the
system is supposed to be pressurized.  Any leakage, coolant or air will
result in an ineffcient water pump impeller and poor flow and thus poor
cooling, depending on the severaity of the leak etc.

I hope this solves or leads to the solution of your trouble, My second
thought is about the guagel..

On those really obscure problems, and I have done a few, the vehicles temp
guage was fried. It was an Audi. When the guage read "hot" I verifyed the
temp w/a second gauge.The guage was lying.  The reason were we confused is
that the cooling fan didn't come on. The owner had replaced every thing
before I got involved. Well, I'm just suggesting before you begin replacing
things to consider this too. Tip.  Most garages have a temp guage that you
just point to the thermostate housing and it reads the temp.

  As to why, the dealer parts guru stated the the guages were usually trash
if the motor every overheated and "pegged" the gauge.  Not a technical
response, uhh technically speaking, but I thought I'd pass it along.

Mark Keller
91 Carat WLE


>Subject: Wasserboxer Overheating
>
>When I bought my 1991 Carat with 125,000 miles on it, the VW dealer
>who did a prepurchase inspection said it  "already had the head job".
>
>A couple of months later, the red coolant light would go on, and shortly
>thereafter the temperature guage would climb.
>
>I've replaced the coolant and bled the system per the Bentley, twice.
>There does not seem to be any coolant loss, still, we've looked all over
>for leaks,
>including the heads. My mechanic insists it can't be air in the system,
>but
>has no other suggestions. Can anyone give me some help?
>
>I have limited e-mail and cannot get to the web to search the archives.
>Please send cc: any replies to me at the address above.
>
>Thanks,
>
>Scott Davis
>
>sdavis@smithgroup.com