Hey, everyone!  I just bought an '85 Vanagon about a month ago from a shop
in Virginia called "Air Cooled Recycling Unlimited"... 255k miles or so on
it, with (he said) about 55k on the engine since the last rebuild.

Driving it from there to a friend's place in Ohio, I met several folk who
approached me about it... and I commented to my friend, when I pulled in,
"Whoa, I thought I was buying a van, but it's like I bought membership
into a club!" ;)

Another friend told me about this list, so I figured I'd drop in and say
hi to y'all, and ask a question that's plaguing me a little bit:

If I drive for more than about 20 to 25 minutes at a stretch, my van
starts to lose power, almost like it's overheating.  I know that the
thermoswitch on my radiator's bad (I wired a manual switch in the cab for
it, anyway, because I'm planning on taking it across-country and I don't
want any inadvertent overheating as I'm climbing the Rocky Mountains
toward Denver), but even with the switch in place and working properly I'm
still getting the problem.

Neither the temperature gauge nor the temperature warning light comes on
while this is happening, I just lose power and have to pull off the road
somewhere until it cools down.  (25 to 45 minutes later, it starts right
up, has no problems, full power again.)

Has anyone else had this problem?  Does anyone know what might be causing
it?  I'm thinking of replacing the thermostat in the water pump, but I
don't know if it's truly heat related or if it might be something that the
computer might be screwing up?  (I have cleaned the O2 sensor with brake
cleaner, as suggested by an ASE mechanic friend of mine, but it didn't
make any difference.)

Any insight will be gratefully appreciated -- thanks in advance!

-Kyle Hamilton