Date:         Tue, 3 Dec 96 21:46:21 EST
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         jag@cs.rochester.edu
Subject:      Re: thermostats, Was:  Diesel "stumbling

Not all thermostats are created equal! Particularly for the vw inline 4
diesel I have found that several brands of  thermostats don't
work -- even when new!!

Good thermostats:
	Behr Thompson
	Wahler

Not good in my experience:
	Motor craft
	Stant (or stent or something like that)

The not good ones have a weak spring (compare your new and old thermostat
at the FLAPS before buying), and at high rpm the water pressure from 
the pump forces the thermostat open regardless of temperature.
This causes the temperature to drop dramatically. For my last "bad"
brand (Motor craft) it happended between 55 and 60 mph in the bus.

/Martin

At 03:36 AM 12/3/96 -0600, you wrote:
>P.S. Thermostat seems to be stuck open, little heat and the needle doesn't
>move off cold ( I know the guage does work after taking the car over the
>mountains).
>
>Best,
>
>Bill Lund

Austin (austins@ix.netcom.com) writes:
Fix it now!!!

This is a 'minor' situation that can (will) cause big problems; a
stuck-open thermostat will increase engine wear like you wouldn't believe -
the poor thing never runs at design temperature, rather lt's constantly
running as if it has just been started (& please don't ask how I found out,
at least it wasn't the Vanagon). Also, thermostats have a bad habit of
getting 'lazy', i.e. they open too soon (or actually never completely close
when cold) and the engine consequently starts taking a l.o.n.g time to warm
up. Keep track of what your gauge is telling you, believe it, & replace the
thermostat as soon as it starts getting lazy (cheap,~ $10, & can be done on
a Vanagon in ~ 1/2 hour).

Austin