I have been using my '87 GL Westy as my daily driver for the past 5 months.
I am the third owner and have owned it for three years.  It currently has
under 80k miles.

Recently I encountered a problem that I hope this group will assist me in
solving.

While driving yesterday, the red temperature light came on; the temperature
needle was about one-third to one-half of the way up.  I immediately pulled
over, shut the engine off, and waited about five minutes.  I restarted the
engine and everything appeared to be fine, but about two minutes later the
same thing happened.  I drove to the nearest exit (about 2 miles) and drove
to an Ames located quite near the exit.  I checked the level in the coolant
reservoir and it appeared to be empty.  I went into the Ames and purchased
a gallon of Prestone coolant - the only brand they had in stock- and filled
the reservoir.  I was surprised that less than one-fourth of the jug was
needed for the reservoir  to reach the "max" level.  I started the engine
and let it run for several minutes to see if the level in the reserve tank
went down.  It did not, so I closed things up and drove away.

About three minutes later, the light came on again and the needle was below
the half-way mark.  I checked the reserve tank level and it was still at
the "max" level.  Against my better judgement, I decided to proceed to my
destination which was about seven miles away.  The light remained on the
entire time, but once again the needle did not go beyond the half-way mark.
I made arrangements to borrow car and garaged the vanagon at my destination
after once again checking the coolant level which had not change.

I have limited mechanical abilities, but am willing to give most anything a
try.  For financial reasons, I would like to avoid taking the vanagon to a
mechanic unless this is absolutely necessary.  Given the location of the
van, the nearest  VW mechanic would be at a small dealership five or six
miles away.  I have basic metric tools and can purchase parts from a local
parts store that specialized in foreign vehicles or order from one of the
list vendors.

Any help - the more detailed the better- will be greatly appreciated.
Thanks in advance for whatever assistance you can provide.

Dianne