----- Original Message -----
Sent: Wednesday, January 24, =
2001 2:58
PM
Subject: Coolant air, overflow, =
fried
head gasket, "burping" out air (long)
Great list. Your advice (and =
patience with
my first post) please:
I'm now the proud owner of an '86 =
Westy, bought
from a guy who'll remain anonymous. He lives 950 miles away and =
I drove
that newly purchased van all the way back to my home in St. Louis =
fighting coolant overflows and the blinking red light.
Before I bought it, PO did flush and =
fill, then
later a radiator replacement. He worried that not all the air =
was out
yet and advised I stop and "burp" the expansion tank if the blinking =
light
showed low coolant.
The engine ran (still runs) great, =
plenty of
power. But after only a few miles, she spit a lot of coolant out =
of the
fill (license plate) tank. (I trailed a nice steam cloud as it =
hit the
muffler). Following PO's advice, I would "burp" =
the expansion (with
pressure cap) tank. Lots of "air" would come out. This =
went on for
many, many miles: coolant overflow and/or blinking red light, =
find a
place to stop, "burp" tank, sometimes add coolant. The =
intermittently
overflowing fill tank would leave a nice mist of coolant on the back =
window at
interstate speeds.
Maybe you are laughing now. At =
about mile
600, I realized that "burping" the expansion tank of a hot engine was =
just
flashing a lot of the coolant to steam (as it went from 14psi or =
whatever to
zero) and the "bad air" I was letting out was steam and that I was =
probably
forming steam voids elsewhere in the system as well. Very stupid =
of
me. If anything, stopping every 15 miles to make the problem
worse. Perhaps I define "knowing enough to be =
dangerous."
Engine runs great still, but now I =
get
intermittent white smoke from the tailpipe and water dripping from =
it.
Even after I stoped my dumb "hot burping," still got a lot of air =
coming out
of the expansion tank (replaced the pressure cap about halfway through =
the
trip, hoping that was the problem). Evidenced by a train of =
little
bubbles entering the fill tank when the engine was hot.
I am fearing that my =
hot-engine-burping, or maybe
the flush and fill or radiator replacement led to overheating and a =
bad head
gasket. I believe the PO's statement that the recently redone =
heads were
fine before. I checked the temp gage every 10 seconds, I swear, =
and it
never got over 3/4 scale (stopping, slowing) and usually (on the =
highway) sat
right over the little light.
Something I learned that may help =
you: The
low coolant light is a "latch" circuit: It stays on until the =
ignition
is cycled off no matter what--I could often just pull over, turn off =
the
ignition, restart, and no blinking light. I attributed these =
transients
to steam slowly venting out of the expansion tank (that little valve =
is very
small).
Please advise: Have I fried a =
head
gasket? How can I tell if combustion gases are getting into the =
coolant
and forcing it out? I checked the archives: Nobody has =
warned of
"hot burping." Is it so obvious (or am I that dumb)? Can =
these
engines really run so well when blowing/sucking coolant into/out of =
the
cylinders?!
BTW, I'm not looking to blame the PO =
or anybody
but myself. Just looking for advice on cause/diagnosis, and =
perhaps to
warn others. Feel free to highlight, make fun of, or discuss in =
detail
my ignorance.
Thanks,
Steve Gough
'86 Westy
gone but not forgotten: '69, =
'72
Beetles