I'm not sure if I should post here or a new thread, but the problem came back. Air must be getting in somewhere. I'm fairly certain it can't be the heater core because there's no anti-freeze inside the car, I checked the oil to see if it was discolored(head gasket) and it seemed fine. It was a bit low, but it does that fairly often(is that a sign of bad head gasket?). I see no leaks anywhere. The only thing I could think of was to ask who helped me with the water pump installation. He said one of the small bolts(not the long ones) had a head snap off when he got it tightened. So I thought maybe this was causing coolant to leak out and air to get in, but I see no coolant on the water pump anywhere. There is some below it stained where it was leaking bad before, but the water pump still looks nice and new. Radiator still looks almost completely full too. Where as before it was draining down. I really can't seem to find any problems anywhere other than the fact that air is somehow getting into the system somewhere. Any help would be greatly appreciated. Really can't sell this car until it's running again and I NEED a new car. My college work load is massive this semester so I will be driving a LOT.