Tedro951

It's cheap enough to buy the kit with fluid for testing for combustion gasses in the cooling sys. Takes a couple minutes and you can do it in a tux.

333pg333

We have been having similar symptoms with our car but of course it has a metal headgasket and therefore we can keep running on the day. I would have thought that if it's the stock gasket it will just blow and not reseal? Worth installing the secondary bottle or overflow tank too. Also agree on improving your oil cooling system Eric. (btw you use a 20w/50 from memory?)

Eric_Oz_S2

Patrick

I use a 20w60 synthetic high zddp oil and change after every 2 track events.

I drove the car home and it didnt leak anymore, but I could hear gas escaping from the radiator cap. Strong fuel smell from coolant. So it seems to be leaking combustion gases, but only ever do slightly under normal road cruising.

Eric_Oz_S2

...

odurandina

As a possible short term fix, does opening the pressure release valve
reveal & eliminate the problematic air pocket that forms at the top of the engine,
which i assume, causes (very bad) variances of temperature/s
during the early stages of a failure, (then) exacerbates the condition?
Does the air pocket more or less confirm a failed head gasket?

*i'm sure people cringed when i used Blue Devil head gasket sealer
for the final 51 k miles for my 968 (pre-LS).
It required 2 treatments to wring out those final miles: great to be able
to keep costs for keeping the car on the road low for those last 2 years.
i no longer drove it hard. But, took it everywhere between
New England, the midwest, and Florida.
After the 2nd treatment, the engine ran noticeably hotter in traffic on hot days.
It didn't matter, as once i was ready to have the LS put in,
the 3.0 was to a await a new home (for someone's turbo build).
The installer was able to sell for a good price and local pick up.
i wonder what the cooling ports looked like.
The radiator was scrapped.