Date:         Fri, 28 Feb 1997 09:28:36 -0800
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         natasha!mholser@Adobe.COM
Subject:      Re: Too hot or not?

> From vanagon@lenti.med.umn.edu  Fri Feb 28 07:30:37 1997
> >Received: by adobe-uucp.corp.adobe.com; id HAA20183; Fri, 28 Feb 1997 07:26:04 -0800
> Date: Fri, 28 Feb 1997 09:26:43 -0600
> Originator: vanagon@lenti.med.umn.edu
> From: galba@premier.net
> To: vanagon@lenti.med.umn.edu
> Subject: Re: Too hot or not?
> X-Listprocessor-Version: 6.0c -- ListProcessor by Anastasios Kotsikonas
> 
> Randy--
> 
> That red light does not indicate how hot the coolant is.  It is a level
> If the
> coolant level seems okay, and bleeding for air bubbles doesn't solve the
> problem, then it could be one of two things.  1) bad sensor or 2) weak
> coolant concentration.  

Actually, a *weak* solution will not flash the light, but a too-strong 
solution will.  Kinda backwards from what you want, but the sensor reads
the current flowing between the two probes.  Water, with normal contaminants
in it, is a fairly good conductor, but antifreeze is not, even mixed with
water.  It is possible that the guage is calibrated to sense too much
current as well, and get you a reading of too little antifreeze, but it
is more common for folks to figure that if 30% antifreeze is good, then
100% is three times better.  Don't.

If you have an air-bubble, this is usually a symptom.  Start keeping a close
watch on this tank.  Never let the fill tank run dry.  The later (post 85)
Vanagons have a very complex and effective setup for getting air to migrate
out of the system.  If you get air into the system, it is a sign that something
is really wrong -- at best your cap on the reservoir tank, at worst leaking
heads.  You should get a test for exhaust gas in the anti-freeze.  If your
mechanic looks at you like you're growing a carrot out your nose, go to a
NAPA store and just buy the tester.  It costs about $30.  A pain, but many
mechanics are in that profession because the can't hold the counter-job
at Micky-Dees.  Get the tank cap tested.  If you are not strapped for cash,
just get a new cap from the dealer.  The cap is pretty expensive -- like $30,
and it might be better to get the cap and tank together -- they don't cost
much more as a pair, and the tanks are prone to small cracks that cause
the failure of the air-bleed process designed into the system.  Actually,
almost any leak will cause the system to fail to purge air, so be on the
lookout for even tiny leaks.  Your system needs to be air-tight to suck the
coolant up from the overflow tank behind the license plate.

malcolm