[steve meltzer]

Finally got back to the car last nite and, at Southern's request, used the restrictor in lieu of the T-stat, though no one thought it would save the day. Using the Stant coolant system pressure tester, the system again fairly quickly lost pressure (again, about 5# loss in 10 minutes). With another observer to confirm my findings, we found no leaks and no clear evidence of a leak after carefully checking all possible areas (tank, WP, hose, connectors, Temp sensor in the manifold, etc.)

Fired the car up and again, a rapid rise to about 105C. The car was sitting in my garage with the throttle changing constantly between idle and about 3K. (even got a personal visit from my friendly police that a neighbor complained about the noise from the sidepipes!...my ex was right, I'm no better than a common criminal!)
Decided to see if there was any air in the system, tho' it was checked earlier, and, viola, bubbles came from the sensor housing. Raised the front end of the car, re-bled, and got the same result everytime....even with the system bled thoroughly, firing up the engine resulted in new "air" in the system! Didn't matter if the car was jacked up to "bleed" it or not...same thing. Seems like maybe a bad head gasket, with the creation of combustion gases within the coolant. I can't explain the data in any other way, and I'm confident that this isn't a T-stat/restrictor issue, the coolant moves well in the tank with the cap off, and I have bled the system a number of times, both on and off jack stands. thanx steve