I drove my 1.6D ASI camper last summer in the mountains and deserts of
Arizona.  Several times on long climbs, the temperature gauge needle was
more than halfway from the LED to the UPPER end of the gauge.  The fan never
came on.  Yes, it does work and it does have the proper switch.  I was able
to maintain at least 35 MPH, so there was some decent air flow through the
radiator.  This leads me to believe that the Vanagon cooling system is quite
a bit oversized for the thermal load of the diesel engine.  I wouldn't worry
about the 87C thermostat during winter months, but I would still change back
to the 82C (80 if you can't find one) when warmer weather arrives.  And
now....

Anecdotal evidence of diesel engine efficiency:  I drove my diesel camper
for quite a while with a rusty radiator.  Here in the San Diego area, April
weather is mostly cool.  I wanted badly to replace the radiator before the
summer camping season, as I like to travel to Phoenix and am still hoping
for my first Baja trip.  When we finally replaced the radiator, very little
came out with the chunks of rust.  The radiator was completely plugged.
Apparently, the engine received enough cooling from the heater circuit to
maintain normal operating temperature.  The temperature gauge needle never
went above the middle of the LED.  With the new radiator, I replaced the
stock 82C thermostat with an 80C model.  Since then, the needle sits right
at the bottom of the LED when the engine is warmed completely.

Mike Snow

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf
Of Michael Pidcoe
Sent: Wednesday, January 31, 2001 6:04 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Diesel heater question

Well, I replaced the thermostat with an 87 degree dealy.  The one that came
out was has the following markings;
337/437-160
That's it.  Anyone know what that means?
The short story is the water temp is much higher according to my indicator.
 The needle has moved the width of the warning light.  It used to be just
below the light and now it is just to the right, maybe a tic higher.  It was
pretty warm in PA today so I will see how it goes when the chill comes back.
 My concern now is for the summer but I guess that can wait!  I did not hear
the radiator fan come on so hopefully I am OK.
I think I read somewhere that the fan switch should match the thermostat.
Any thoughts on that?
Thanks for all your suggestions, especially Mike, Mark, Joe and Donna.
I'll post again (I'm sure y'all be holding your breath) with an update.
Mike Pidcoe