I have a 2003 f150 that has a cooling problem. I have absolutly no heat in cab until the gauge pegs out in the red then the thermostat opens and temp drops in the engine and get coolant into the heater core. Ive changed the thermostat twice now, once its overheats for the first time then the stat stays open and everythings fine. anyone have suggestions how to fix this problem?... The stat can't be put in backwards can it?

 

The long end of the thermostat should go toward the engine block/hot parts. The more flat surfaced part should go toward the radiator/hose. If it seems complicated just turn it around and see. The new thermostat should first start to open close to its temperature. you can put it in a small metal pan and watch it open on your kitchen stove to make sure it works. Try your first new one first so you don't take it all apart first. As the water in the pan aproaches boiling the thermostat should open. Notice I said aproaches, not boils. Shut off the stove when the thermostat is fully open and watch when it closes. You can use a thermometer if you have one. Just don't scald anyone. Antifreeze helps with the boiling thing in the car. A lot of things can upset the cooling, clogged radiator, bad water pump bearings, burned cyl head gaskets, even cracked heads. Constantly overheating your motor isn't good. Damage will happen if it continues this way. A bad water pump bearing can cause damage to the impeller pump on the water pump messing with water flow, but usually it leaks perty bad and is very noticeable when you look to the front of the car under it. One of the simplest things overlooked is the sealing condition of the system. If it leaks psi the cooling system won't work worth a hoot. So test it, if you don't have a tester ask em to test it for you. No matter how hard you work on your truck if you don't test the psi holding condition of the system you can't be sure it's fixed, even if it seems to work ok now. You can still end up broke down on the marbles later on some night.