thanks!!!  i think that's really the explanation that i'm looking for.

i'm crossing my fingers that it's not a leaking head.  in wonder - in
this situation, will the van begin to overheat immediately???

dusty.
On Feb 5, 2006, at 8:51 PM, John Rodgers wrote:

> Dennis is exactly on target.
>
> Check the little hose from the expansion tank cap to the over flow
> tank,
> be sure it doesn't have a leak. Then fill the expansion tank, put the
> cap back on. Run the engine until warm. As it warms, the coolant will
> expand increasing the pressure on the cap and the coolant will flow
> into
> the overflow tank. Shut the engine down, allow it to cool. If there are
> no problems with the cap or hose, the coolant should be siphoned back
> into the expansion tank as the coolant cools down. The overflow tank is
> vented with three holes in the back side of the tank towards the rear
> of
> the vehicle up at the top.
>
> However --- if the coolant exits the expansion tank, and the coolant
> level in the expansion tank drops with nothing to replace it, then in
> all likelyhood - as Dennis has said - you have a head leak and
> combustion gases are escaping into the coolant, collecting in the
> expansion tank, and pushing the coolant out. The over flow tank then
> becomes a vent for the expanding combustion gasses and displaces so
> much
> coolant that it cannot be recovered. As the engine cools after shut
> down, the exposed end of the hose in the overflow tank simply sucks air
> and  because the ends of the probes on the sensor are exposed, and the
> system reads an open circuit like that as "infinity" resistance ....
> and
> the red LED on the temp guage comes on.
>
> Go Luck.
>
> John Rodgers
> 88 GL Driver
>
>
> Dennis Haynes wrote:
>
>> Nope!
>> Either the system is not fully filled, (air in system), or the
>> pressure
>> cap is not holding, or most likely you have an internal head leak
>> filling the cooling system with combustion gases.
>>
>> Dennis
>>
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
>> Behalf
>> Of dusty edwards
>> Sent: Sunday, February 05, 2006 1:21 PM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Blinking Coolant Light Mystery (to me)
>>
>> so, the coolant light seems to begin blinking once the van is warm.
>> i've learned a little about this scenario while searching the
>> archives.
>>
>> the fill tank is full, but the expansion tank is at (or below)
>> minimum..........should it be that way?
>>
>> any suggestions?
>>
>> thanks for your help!
>> dusty.
>>  |___|_|_|__\
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>>  "(o)-----(o)--"
>>
>>
>>
>>
>>
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