+1 with the thermostat. It should be 1/2 all the time when warmed up. If you have air in the system then the heater doesnt work so good as its the highest point in the system. When the car is cold you should check to see if there is pressure and a little heat in the outlet hose of the radiator to the engine. When the car is cold there should be much pressure back to the engine as the thermostat should be closed and not flowing much through the radiator. Let me know if you got questions... Lee |