You probably need to check or replace the thermostat in your first
Vanagon. I had experimented with quite a few thermostats before.
One of them had this symptom. I determined that the coolant temp
should be kept as constant as it can. Cylinder wear will increase
if the temp is too low. I tossed the problematic thermostat and
have been happily reading my temp gauge being more stable as it
should be. 

David

--- On Thu, 10/8/09, Loren Busch <starwagen@GMAIL.COM> wrote:

> From: Loren Busch <starwagen@GMAIL.COM>
> Subject: What Should I See On the Temperature Gage?
> To: vanagon@GERRY.VANAGON.COM
> Date: Thursday, October 8, 2009, 9:58 AM
> Okay, I've posed this question before
> in a slightly different form but here
> goes again.
> I'll describe the appearance/behavior of the temperature
> gage on two
> different vehicles, both running 21.L WBX w/automatic
> tranny, both with the
> GL dash (small temp gage under the tach)
> First vehicle the needle of the temp gage rises slowly when
> starting from
> cold, never gets up to the LED, stays just below in normal
> outside temps.
> When climbing steep mountain passes the needle will climb
> up to the LED and
> at just above the LED the fan will come on.� But when
> going down the other
> side of such a pass the needle drops way down almost to or
> sometimes against
> the bottom mark on the gage.� Normal running at
> highway speeds in the flat
> the needle will be about half way up to the LED, maybe a
> little higher.
> Second vehicle the gage, from a cold start, quickly runs up
> to about the
> center of the LED and stays there.� Rises a little to
> the top of the LED
> when climbing a mountain pass, fan may come on if the
> needle gets to the top
> of the LED.� But running down the other side of the
> pass needle stays up at
> the LED, never drops down to the bottom like the first
> vehicle. And needle
> stays centered on the LED when running at highway speeds on
> the flat.
> I'm assuming that the second is correct and the first has a
> thermostat that
> is sticking open or at least passing more coolant to the
> radiator than it
> should.� And that the second is the way I'd
> expect:� Thermostat opening and
> closing based on the temperature of the coolant and keeping
> the engine at a
> constant operating temperature.
> So, which is normal? Which is 'right'?
>