Volks-folks,

Last week I asked about the correct thermostat for my type-IV '78 bus
with 2000cc AFC engine.  I only got one response, from Sean Bartnik
(thanks Sean!) who said that, regardless of what Bentley said and
whether or not it was a typo, he had used the Wahler 85-90'C
thermostat on both 78 and 81 t-IV engines, and never had a problem
with it.

Well, this weekend I went out to install my 85-90'C thermostat, and
discovered when I pulled the old one that it was indeed a 65-70'C
thermostat, an original VW part, not a Wahler replacement.  Huh?  So,
I went and pulled the one off my parts bus, and it was an 85-90'C
Wahler.  The difference between the two is that my daily driver still
runs, and the parts bus' engine is siezed.

I also notice in RMMW catalog, the thermostat listed for the t-IV
engine is the 85-90'C thermostat.

So, again I ask, what's going on here?  Bentley says 65-70'C.  The old
thermostat that came off my bus was 65-70'C.  But VWoA sent me an
85-90'C thermostat as a replacement.  Is it right?  Or will my bus be
running 20'C too hot?  Or does it normally run above 85'C anyway, even
if it has a 65'C thermostat in place, and it's just a question of how
warm the engine is when the flaps start opening?  What happens in the
winter coasting the downhill side of a mountain?  Could the
85'C-controlled flaps close when the 65'C-controlled ones wouldn't?
Did VW "change their mind" between the buses and the vanagons--are
the vanagons actually spec'd for the 85'C thermostat?

Should I try tracking down the 65-70'C part???  Or just use the
85-90'C one?

I'm so confused!
Rodney