From: Stephan A. Zweidler, SteveZ@psu.edu
It took me a while to finally figure out what caused my head gasket to leak but here is the exact time line.
NOV97 - switch to Mobil 1, 5W-30
DEC97 - have dealer do 50K service and flush coolant (they don't replace radiator cap {foreshadow})
DEC to JAN - intermittent heat during cold starts, and smell of burning oil at stop lights
mid JAN98 - start refilling overflow bottle because it was "gurgling" or as some people have described "boiling" immediately after engine is turned off.
end JAN98 - oil leak progressing, make appointment to have it replaced.
last nite(early Febuary) - I shut off the (well warmed) neon, it "boiled", then I went to squeeze the upper radiator hose. VOILA ! It had NO pressure in it, and when I squeezed it the overflow tank "gurgled". This meant that the radiator cap was not sealing in the pressure and allowing the system to vent all the time.
SO, here is the deal {Josie and the PussyCats style}
They flushed the coolant in December but didn't replace the original cap which had seated itself onto the rim of the cap mount. When they put the cap back on, there was no way it was going to seal again, so the cooling system never pressurized and eventually boiled a significant amount of coolant out of the system. That meant that there was "void" in the cooling system that deprived the head and upper combustion chamber of much needed coolant for extended periods of time and numerous heat cycles. This (I suspect but will be sure on Wednesday) caused the head to warp and the gasket to fail causing my oil leak.
If anyone out there has a "boiling" or "gurgling" noise when they shut off their neon, it is likely that your radiator cap (not exactly on radiator anymore) is bad, and you could be boiling away precious coolant. Replace the $6 part now and save yourself $$$ later. The cap can be bought at Napa, p/n 703-1447, it's a 16 lb cap made by Balkamp.
It is likely that I will not be able to pin this on the dealer even though it was their negligence that ultimately caused the failure.
Donations will be accepted for the repair though ! (hehe)
Stephan A. Zweidler, President PSU-FSAE, A-mod Super Star (hehe)