Adding some comments on this at a late date, but I fixed my friends 96 contour that was overheating. I chased this for awhile. I replaced the thermostat, and that did not fix it. I took the old thermastat and pulled the coil spring loose, installed it to let the water flow freely, and check the radiator temperature. Guess what, it still over heated. I thought, maybe there is a plug, i flushed the radiator, but flow was really good. I finally took off water pump and checked impeller, but is was fine. After putting the opened thermostat back on, and seeing that after it starts to warm up, the water flows over the resivor, i concluded it was the head gasket. The leak appears when the car warms up, and it pushes exhaust vapor into water side of the cylynders, which pushes out the cooling water. I replaced the head gasket, and problem solved.
