First, I apologize for the long post. I have a 91TT that is pretty stock with the exception of exhaust and the JWT ECU upgrade with boost jets for stock injectors. I am having an overheating problem. At first I thought that I had a bad thermostat because it didnt seem like there was any coolant circulation. The heater would go from very warm to ambient temp. I replaced the thermostat and the problem came back. I took off the overflow hose off the radiator and saw that coolant was coming out of there before the car was even up to temp. I changed out the cap and no difference. I started thinking that it could be a head gasket letting go, so I tested it with a chemical turkey bastor style tester with the engine off and with it on hitting the throttle. Tested fine. Next I thought that it was an air pocket trapped in the system so I tried to bleed it. I raised the front of the vehicle and attached my spill free funnel and filled it with coolant. I ran the car for about 30 min. and it sucked some coolant down. Drove the car and still it started getting hot. I am running out of ideas here. I talked to a few Nissan dealer techs who are considered Z-car specialists and they say the cars are horrific to bleed. Is there a better bleeding proceedure, or am I way off in my train of thought. Any help would be appreciated.