well the car was given to me by my parents about 2 months ago when they drove to idaho to visit my family and i, and apparently blew a headgasket per dealer. well i changed the oil, it looked fine, flushed the line that goes into the surge tank across the motor, it wasnt plugged. drove it to town yesterday to get it registered and everything worked fine the 10 miles going 60, temp stayed at 212. got into town and it shot up and started steaming. stopped at a gas station and put some water in the surge tank to try and get home. got about a mile from home and pulled over b/c it flashed across the dash idle engine, wanted to stop and eat anyway. let it sit for about 45 min and drove the rest of the way home, still flashing idle engine, took it easy on her. not sure if it is a headgasket, hoping maybe something simple like a thermostat. also would it be something as simple as not having the right coolant mixture now that i had to top it off at a gas station. any help would be appreciated. thanks.