Date:         Wed, 11 Aug 2004 10:58:51 +1000
Reply-To:     Stephen Overmyer <S.OVERMYER@UWS.EDU.AU>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Stephen Overmyer <S.OVERMYER@UWS.EDU.AU>
Subject:      Re: overheating weirdness - expansion tank temporarily going empty
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Paul,

Some years ago, I experienced a similar problem to the one you describe
below although mine was probably not quite as dramatic....to begin with.
First happened when I was travelling almost 2000kms from home and the
coolant light started flashing as I slowed down entering a town.
The temp indicator hadn't risen but the light was blinking and the
expansion tank was very low. No change in the level of the refill tank.
I topped up the expansion tank, although like you, when I removed the
cap, air rushed out and the tank partially refilled itself back from the
engine.

I made it home OK over the next 3 days, stopping maybe another 4 or 5
times when the light blinked and again found the expansion tank low, not
empty, but again when the cap was released, coolant flowed back into the
tank.

For the next few months, the problem did not re-appear, although that
was obviously due to the fact the van was only doing relatively short
trips.
But eventually it did come back and then followed two instances of the
engine unable to turn over and start, although in both cases, it finally
did turn over and then started OK.

Next, white "smoke" started coming out of the exhaust and the penny
certainly dropped at that point ;)
A coolant leak and the 2 instances of difficulty in turning over was
probably hydra-lock.

Turns out, one of the heads had a slight crack and coolant was managing
to find it's way into the combustion chamber.
The expansion tank getting low (but returning to near normal level once
pressure was released) was due to exhaust gasses pressurising the
cooling system.
Nothing a replacement head didn't fix...;) BTW, the head gasket was
still fine although I didn't re-use it.

So whilst I trust your problems are of a more benign nature, it does
sound rather similar to my experience 5 or so years back...so be alert,
but not alarmed ;)

Cheers and good luck,
Steve O
NSW Australia
'92 Transporter WBX Kombi (100,000kms+ since the above incident and no
further cooling problems...touch wood ;)
'00 Transporter Double Cab
'03 Transporter Double Cab (work truck)
'78 Landrover Series 3 Soft top (ex-Aust.Army)



Date:    Tue, 10 Aug 2004 08:58:37 -0700
From:    Paul Guzyk <paullist@GUZYK.COM>
Subject: overheating weirdness - expansion tank temporarily going empty

I have an '84 Westy that I recently bought.  Previous owners repair
bills showed varitey of cooling problems.  84,000 miles and it
appears no major engine work has been done.

Drove it from San Francisco to Vancouver last week, every couple of
hours the temp gauge would go "off the chart" and the red LED would
be blinking, mostly while going uphill.

I would stop and check, coolant didn't seem to be leaking out of the
system, but the EXPANSION TANK would be empty!  (the refill tank
would be fine).

Now here's the weird part, I would loosen the cap of the expansion
tank a bit and air would seem to rush out then coolant would rush in
FROM THE ENGINE, not the refill tank.  Once the expansion tanks was
full, I would close the cap.  (the refill tank level would barely
change in this scenario).  After a cool down period, I could drive
again for a couple/few more hours.

Note, the refill tank and hose seem to be working, because at other
times the coolant level of the refill tank goes up and down as one
would expect.

The rad fan works, but it doesn't come on that often.

Before leaving on the trip I bled the system.  I'm concerned that I
didn't bleed it well enough or that air is getting into the cooling
system from the combustion chambers.

Ideas?  Advice?  This is my first water cooled van and I'm stumped....