If the cylinders had a crack causing coolant to leak into the exhuast
then you will see coolant vapor int the tailpipe. That's a worse
sceneario than leaking head gasket. I strongly feel that you have
a head gasket leak. The conbustion gas is leaking through the gasket
into the colling system. The engine may be in need of rebuild.

David

--- John Goubeaux <john@UCSB.EDU> wrote:

> Well, I can reproduce the problem and see that after the car runs at
> idle and slightly higher rpms for 4-5 minutes the cooling system
> appears to pressurize, and along with the flashing red light and gauge
> going to the top I can see coolant starting to trickle out from the
> under the sensor where it goes into the reservoir.  the temperature is
> definitely rising and the reservoir is pressurizing and spilling over
> into the overflow tank.
>
> If it was a head gasket wouldn't I see some other symptoms ?  such as
> vapor from the tail pipe ?
>
> -john
>
> neil wrote:
> > a failed (closed) thermostat?
> >
> >
> >
> > On 7/20/07, John Goubeaux <john@ucsb.edu> wrote:
> >> I have a situation where my 90 vanagon, after running for a few miles
> >> began to exhibit "cooling system problems":
> >> The temp needle went to the top and the red light began to flash. I
> >> drove a little while longer and idled downhill home.
> >> Coolant was leaking out of the (it looks like top of )  pressurized
> >> coolant reservoir and as well as being under what looks like higher
> >> pressure than normal. The car did not appear to be overheating. After I
> >> stopped the engine I could hear pressure noises (what sounded like fluid
> >> shifting around as the engine cooled off)
> >>
> >> Does this point definitively to a head gasket leak? If not what are the
> >> other possibilities?  My coolant reservoir  had signs of leakage around
> >> the top where the sensor fits into it prior to this and this was pointed
> >> out to me by a mechanic.
> >>
> >> Thanks !  -john
> >>
> >
> >
> > --
> > Neil Nicholson. 1981 Air Cooled Westfalia.
> >
> > http://web.mac.com/tubaneil
>

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