The cooling system is under pressure, and will not get air in from
outside. The only place it could be coming from is a leaking head. I had
this problem a few years ago, the agent had to take the heads of a
number of times over a 4 month period before the problem was solved. My
problem(luckily) appeared after I put in a VW recon motor so it was
covered by guarantee. The cause of the problem was that the heads that
were used for the rebuild had been skimmed beyond some or other criteria
and the agent eventually got new heads or better factory recon heads
fitted  to fix the problem. I must admit that it was a very inconvenient
problem and it took a long time for the agent to fix the problem as the
problem did not occur by just driving the car down the road.

Cheers

Jimmy Sanby
Cape Town SA
'89 Syncro
>>> Todd Last <rubatoguy@WORLDNET.ATT.NET> 11/10 8:31 AM >>>
I have an '88 westy that has the following symptoms:

After about 3 hours freeway driving (~4200 rpm) The red led will flash
and
the temp gauge climb to the top of the scale. It appears that the
coolant
tank fills with air - and coolant gets pushed out to the overflow tank -
which fills to above the cap. At some point the pressure starts spraying
coolant out the back of the van.  (Good to keep tailgaters at bay)

After inspecting the engine I found no leaks, but did find a leaky rear
heater core. I replaced the core and thought all was well.

On a test run - sure enough, 3 hours at (~4200 rpm) and the same thing
happens. This time I stopped and kept the motor idling to see if I could
discover anything else. I saw air bubbling into the expansion tank. In
trying to see where the air was coming from, I followed the plastic loop
and
noticed that if I pinched closed the small hose from the right cylinder
bank
to the plastic loop - the bubbling stopped.

Are there places that the cooling system will leak that are not easily
found?
Also, how do you check to see if the heads are leaking?

Thanks,
Todd '88 Westy