I'm still trying to track down the cause of my overheating. Before I began any of this the car would only run hot on long steep hills in 1 and 2 gears. The problem was manageable by turning on the heat. I decided I want to fix it and now the car overhears in normal driving conditions. This is what I have done thus far: remove old thermostat replace with new (checked both in boiling water, old was ok but new was more responsive to temp changes). Next I refilled radiator through expansion tank, ran car with heat on and added more fluid, then I disconnected the return line to expansion tank and filled head with fluid to bleed. Then I replace expansion tank cap. Drove car and it was overheating worse than when I started. Next I replaced the fan clutch. No result. Then I ran the car until it was hot, poped the hood, hit the kill switch and the fan just spun, clutch was not engaged. I put my hand on the radiator and it is cool to the touch. There is pressure on upper hose and it is hot to the touch, lower is not. The cabin heat blows really hot, so I'm assuming my water pump is working. One odd thing I noticed was that with the car warm and running if I disconnect the return line to the expansion tank no water is coming out of it, this makes me wonder about the water pump. Also I broke the prong off the sensor that attaches to my water pump, what does this sensor do? Is it possible that my water pump is bad but still have heat in the cabin? Does anyone have any answers?