Well, I have heard of this before, and I have 1 recommendation:

After a good long run at moderate to high temperature - do not pull to a stop, and shut off the engine.

Your heads are really really hot, and coolant can/will boil in them, causing the overflow you experienced  - because of excess pressure.

After a long run, just let the car sit idling for 5 minutes or so, to allow the coolant to ciculate through the heads as they cool off.

Maybe even give it a bit of throttle to get the coolant to the rad. That'd help.

(Just ask me someday about my trip to BNNTA in Hannibal MO - I became the guru of overheating/overflowing issues)

Now, you should always have coolant in the "fill" bottle, even when cold.

What I do is ensure it is at least a 1/4 to 1/2 full, when cold.

After the overflow you experienced, you should fill the bottle with 50% coolant/water - and try to purge your system of air. No doubt that when your van - with an empty bottle - cooled, it sucked air into the cooling system, and you have to get this out or you could have an air bubble blocking the flow - and cause serious overheating.

Really.

Marshall Ruskin
84 Westy
  ----- Original Message -----
  From: Randy Charrette
  To: vanagon@gerry.vanagon.com
  Sent: Sunday, June 16, 2002 09:28 PM
  Subject: Cooling system level?

  My 87' Syncro did something weird today. I drove for about 45 min. in high 80 degree weather. Engine temp was fine, but when I shut down coolant over flowed in the "fill" bottle and came spouting out of the little holes in the top.I heard it gurgling when this happened. I did not top it off again after this and continued on my day watching it. What I would like to know is- should the coolant be between min. and max when the engine is hot or cold? Right now after this incedent I am running in between the marks at operating temp, and no coolant in the fill bottle when cold. Is this right?

  Randy Charrette
  87' Syncro
  217K

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