Jim, it could be the thermostat and that is the cheapest thing to try
first, however it could also be the radiator.  The Vanagon radiator is a
wear item and it will slowly clog up over time due to internal corrosion
of the cooling system.  It is super over engineered so that it will work
well even it is partially blocked, however it may be that it is just
time to replace it.  My 90 Carat is reaching this point I think as it
seems to be running hotter than it should and everything else is brand
new.  The radiator is original and has 320k miles on it so it owes me
nothing at this point.  Let me know what you find out.

On 3/5/2011 1:15 PM, Jim Felder wrote:
> I have been having a nagging overheating problem over the last several
> months that has led to the replacement of a heater valve, two
> reservoir caps, hoses and a number of clamps. While I have fixed
> several leaks that were showing up after some near overheating events,
> and right now it is not leaking a drop, the problem persists. I have
> done lots of work on diesel and waterboxer vanagons I have had and
> have never had a persistent overheating problem like this.
>
> When I start the car from cold, the temperature needle climbs steadily
> and slowly up past the middle through the 3.4 mark, no matter what.
> Top of radiator, which spews coolant and not air when opened, is cool
> to the touch. Thermostat? I will gamble the money and replace it next
> week when I can get a good one.
>
> Jim
>

--
Thanks,
Ken Wilford
John 3:16
www.vanagain.com
Phone: 856-327-4936
Fax: 856-327-2242