Date: Tue, 2 Jan 2001 21:07:26 -0600
Reply-To: John Rodgers <inua@HIWAAY.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <inua@HIWAAY.NET>
Subject: Re: Request for Help - Overheating Problem
Content-Type: text/plain; charset=us-ascii
Dianne, There are two tanks you have to deal with on a vanagon based vehicle.
While standing at the rear of the vehicle, raise the engine cover. You will see
at the very rear of the space there are two tanks. The one on the left is the
coolant expansion tank, the one on the right is the overflow tank. The tank on
the left...coolant expansion tank...is to be kept tooped with coolant at all
times. When the coolant get hot as the engine runs, it expands, pressurizing
the entire system. The coolant, all expanded by the heat, needs to go somewhere
so the built up pressure opens the expansion tank cap valve allowing excess
coolant to flow through the little tube attached, over into the overflow tank,
which is vented to the atmosphere. When the engine is shut off, and begins to
cool, the coolant shrinks. This results in a pressure drop in the cooling
system, and the coolant is siphoned from the overflow tank back up through the
little tube, through the expansion tank pressure cap, and back into the
expansion tank. It the coolant level is up to specifications, there should be
no problem.
The coolant expansion tank has a sensor that screws into the top of the tank.
It consists of two little prongs that extend down into the coolant. These two
prongs allow the circuit to read the resistance of the coolant. As long as
there is coolant present, the circuit keeps the red light turned off. If the
coolant level drops below the sensor prongs, the circuit turns the red light
on.
The first step in solving you problem is to be sure the coolant level is topped
up in the coolant expansion tank.. Pull the wires loose from the coolant level
sensor and unscrew the sensor. Top off the tank with a 50-50 mix of water
and antifreeze. Re-install the sensor. There is an o-ring under the sensor cap,
so be careful that it seats properly, and the sensor is threaded in correctly.
Next fill the overflow tank to the minimum capacity.
Start the engine and let it warm up, or go drive it.
Once warm, observe the coolant level in the over flow tank. Should be higher
than minimum.
If the coolant sensor light comes on, Shut the engine down, allow to cool, then
replace the coolant level sensor. The sensors give trouble, and it's just a
matter of time before you will have to replace one anyway.
Observe if there is a great deal of air in the expansion tank. If so you may
need to burp the cooling system. The way I do it is to get on a really steep
grade, point the front end down the grade, and with the expansion tank cap
removed, run the engine 2500 to 3000 rpm. There are other methods, and maybe
another listmember will elaborate.
Good luck,
John Rodgers
88 GL Driver
dianne gigler wrote:
> I have been using my '87 GL Westy as my daily driver for the past 5 months.
> I am the third owner and have owned it for three years. It currently has
> under 80k miles.
>
> Recently I encountered a problem that I hope this group will assist me in
> solving.
>
> While driving yesterday, the red temperature light came on; the temperature
> needle was about one-third to one-half of the way up. I immediately pulled
> over, shut the engine off, and waited about five minutes. I restarted the
> engine and everything appeared to be fine, but about two minutes later the
> same thing happened. I drove to the nearest exit (about 2 miles) and drove
> to an Ames located quite near the exit. I checked the level in the coolant
> reservoir and it appeared to be empty. I went into the Ames and purchased
> a gallon of Prestone coolant - the only brand they had in stock- and filled
> the reservoir. I was surprised that less than one-fourth of the jug was
> needed for the reservoir to reach the "max" level. I started the engine
> and let it run for several minutes to see if the level in the reserve tank
> went down. It did not, so I closed things up and drove away.
>
> About three minutes later, the light came on again and the needle was below
> the half-way mark. I checked the reserve tank level and it was still at
> the "max" level. Against my better judgement, I decided to proceed to my
> destination which was about seven miles away. The light remained on the
> entire time, but once again the needle did not go beyond the half-way mark.
> I made arrangements to borrow car and garaged the vanagon at my destination
> after once again checking the coolant level which had not change.
>
> I have limited mechanical abilities, but am willing to give most anything a
> try. For financial reasons, I would like to avoid taking the vanagon to a
> mechanic unless this is absolutely necessary. Given the location of the
> van, the nearest VW mechanic would be at a small dealership five or six
> miles away. I have basic metric tools and can purchase parts from a local
> parts store that specialized in foreign vehicles or order from one of the
> list vendors.
>
> Any help - the more detailed the better- will be greatly appreciated.
> Thanks in advance for whatever assistance you can provide.
>
> Dianne
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