I don’t know specifics on the thermostat but it was installed by a shop
that specializes in Vanagons.  I will ask them when I take it back for
repair.

We continued to destination, temp gauge was all over the place though never
too hot. I could not correlate with anything including turning front heat
on and off. Oil temp stayed steady at around 200F. Ambient air temp was 45F
not very cold. I will check the bypass valve tomorrow.

Thanks,
Mark

On Fri, Jan 21, 2022 at 4:42 PM Dennis Haynes <d23haynes57@hotmail.com>
wrote:

> As the Vanagon has such a massively, oversized cooling system along with
> an extremely large heater core, getting hit with cold outside air, keeping
> the engine up to temperature can be a challenge during very cold weather.
> VW became aware of this early on and the fix was the series "F" thermostat.
> This stat features a delayed but fast acting response to temp and the disc
> that seals the is further gasketed to prevent any bypass while closed. So
> do you have the correct t-stat? Further, for the correct stat if not of the
> Vanagon specific design, the lower disc can be too large diameter and cause
> the stat to wedge and get stuck open. Also, as the bypass will close too
> early from this excessive cooling will also result from the lack of mixing
> the hot coolant leaving the engine with the cold coolant coming from the
> radiator. The thermostat set up is really a mixing valve and part of the
> goal is for the coolant to always be flowing through the engine keeping the
> heads and case at the same temperature.
>
> Next, on top of the thermostat is that small hose and bypass valve. Make
> sure that valve is closed.
>
> Try closing the heater valve to see if that brings the temp up some and
> next step is block off part of the radiator.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List <vanagon@gerry.vanagon.com> On Behalf Of Mark
> McCulley
> Sent: Friday, January 21, 2022 3:18 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: On road, Having problem, coolant related
>
> Thanks Ken. Not optimal, I know but is it safe to continue? Loaded up for
> 2 days camping with wife and dogs. 75 miles to destination, 40 to get home.
>
> Sent from my iPhone
>
> > On Jan 21, 2022, at 12:11 PM, kenneth wilford <kenwilfy@gmail.com>
> wrote:
> >
> > 
> > Sounds like thermostat has failed open.
> >
> > Ken
> >
> >> On Fri, Jan 21, 2022, 3:04 PM Mark McCulley <markmcculley@gmail.com>
> wrote:
> >> This is a weird one.
> >>
> >> Coolant gauge started going LOWER while driving at 65mph for 30 min.
> Pulled over to check it out, by then gauge was like it was a cold engine.
> >>
> >> -GW expansion tank is full.
> >> -One of the 2 hoses from engine to radiator is cold.
> >> -Radiator is cold.
> >> -No coolant leaking.
> >> -Oil looks good
> >> -I opened bleed screw on radiator and no air, just coolant.
> >>
> >> After stopping 10 minutes I started van and temp came up to normal and
> radiator got hot. Then a get running a few minutes the temp gauge went back
> down.
> >>
> >> I recently had the entire cooling system renewed, new everything.
> >>
> >> I have the rear heater core out and both hoses are plugged
> >>
> >> Ideas?
> >>
> >> -Mark
> >> 87 Westy
> >>
> >>
> >>
> >> Sent from my iPhone
>