The gauges in the vanagon suck.  I had a similar problem and replaced
everything you replaced and more and then i took it to a shop and they
tested the temp with an infrared gun and it was'nt overheating.  They sell
teh guns at radio shack for around $50 and they should be the first part
you buy when you suspect your van is overheating not the last.  If you are
overheating the gun will help you determine where in the cooling system
you are hot.  The voltage regulator at the back of the insturment cluster
may also be causing your temp gauge to be off.  It is easy to
check/replace.  See bentley for instructions.

Andrew

On Tue, 2 Jul 2002, Markus Kruse wrote:

> Maybe someone can enlighten me.... i am totally out of ideas...
>
> Bought the 89 wolfsburg two years ago and the temperature gauge was almost
> always at the bottom end of overheating. Since then i have replaced almost
> everything (exact description following). It is still riding at just below
> the lower overheating mark until I go highway at about 4,000 rpm and then
> the temperature gauge comes down to a little above the light in the
> temperature gauge in the pannel... as soon as i am back in stop start
> traffic it goes up again... I am not running with air conditioning and
> there is no air in the coolant system.
>
> Here is everything that I have replaced or checked on....
>
> 1. New Radiator, new lower temp sensor for fan. (Fan working fine both
> stages). (comes on once i a while)
> 2. Installed all New heads, piston rings (the old heads were both junk,
> cracked in between each valve, so probably overheated)
> 3. Good newer waterpump, no visible wear on it at all
> 4. New thermostat
> 5. No cracks in overflow or coolant reservoir
> 6. new rear heater core
> 7. correct voltage at the temperature gauge in instrument panel.
> 8. not using any coolant.
>
> Any ideas would be super!!!! I am totally out of ideas.
>
>
> Markus Kruse, Ph.D.
> World Wide Arts Resources, Corp.
> absolutearts.com / wwar.com
> 761 Franklin Avenue
> Columbus, Ohio 43205
> USA
>
> Tel:  614-221-7661
> Fax: 614-221-1933
> www: http://wwar.com
> www: http://www.absolutearts.com
>