I just recently got a 94 GT. The guy I got it from said it had a blown head gasket. Normally if you have a blown head gasket, there is water in the oil, smoke coming out of the exhaust pipes, and the motor overheats fast. In my case, the motor doesnt really overheat that fast. I can run it hard for around 10-15 minutes before it goes above normal on the engine temp guage. The car doesnt smoke, has no water in the oil, and runs fine. When you open the radiator cap and the reservoir cap, it seems like the water has a brown residue, maybe from rust inside the radiator. When the motor starts to overheat, you can pop the hood and the hose going to the water pump will be really tight. Could this possibly be a clogged or faulty thermostat?? The brown residue could have clogged it up. Or is it a blown head gasket?? Please help because I am really puzzled.