Thanks to all who responded to my questions and gave me feedback on my
various (amateur..) dianosis of my cooling problems:

Dave Schwarze suggested that I replace the temp sensor on the thermo since
it may be misreading somewhat and is a cheap part to replace. The part
is $10.00 at VWOA, so I'll probably do this just to remove one variable.

Dan Houg mentioned that I may be concerned if my heat waits until the
thermostat opens - my understanding of the cooling system (again, note
my amateur status..) is that the coolant doesn't pass through the
radiator (and thus the front heat exchangers?) until the thermostat
hits 85 degrees C - up until this point, the coolant simply circulates
in the engine core so that you don't remove the heat needed to warm
the engine to proper operating temp. Once 85C is hit, the thermostat
opens a valve which effectively starts passing coolant through the
radiator, thus allowing heating to occur.

Actually, now that I think about it, I'm probably mistaken here - the
heat comes from the heat of the ENTIRE coolant supply, thus even though
it's not CIRCULATING through the radiator (since the thermo valve is
closed at the end of the radiator return hose), ALL the coolant in the
system is heating up, so you would have heat in this case.

Perhaps I need to take fluid and/or thermal dynamics 101?

Dan also mentioned putting a regular thermometer in the expansion
tank (careful of spitting coolant) - this sounds interesting. Anybody
know the proper temp (or range) for the coolant?

Dan also mentioned replacing the thermo o-ring - this could explain
the white residue on the thermo housing - sounds good.

Joachim Beek mentioned that his Scirocco lost a water pump, and
up until then there weren't any cooling problems - I agree, I don't
think my pump is bad since I appear to be getting proper circulation,
etc.

Alistar Bell mentioned that the later model Vanagon (mine is an 89)
might have plastic components that cannot be rodded out. Anybody
have any ideas here?

Finally, if I do decide to buy parts, is there a difference between
a parts shop that says a (for instance) radiator is "OEM" and sells
for $275 versus a radiator from the dealer which sells for $415?
Would I have "fit" problems with the non-dealer part in some cases?

>From what I now know, there is no difference between the OEM and
dealer parts, although I am suspicious. Comments, anybody?

Continuing to run warm....

Steve

-------------------------------------
Steve Wall (wall@mcm.com)
Mellon Capital Management Corporation
San Francisco, CA