HEATING & COOLANT ISSUE

If you are pushing coolant out the overflow while not overheating, that sounds like a bad head gasket. If pressure from the cylenders gets into the cooling system, that is what it will do. It will also have an affect on the heater. Usually it is caused by an air block. Have that checked. As far as the heat, start the engine, let it warm up with the heater on high, and feel both heater core hoses. If both are hot, then you need to check the blend air door. It is near the heater core and determines if you get heat or AC into the vehicle. If it is stuck, that will cause your problem. However, that has nothing to do with the coolant coming out the overflow. With the engine cold, remove the radiator cap and start the engine. If coolant comes shooting out, you have a headgasket problem.

I'm glad to help. I just wish I had better news. What you said can be true. If the headgasket leaks into the combustion chamber (cylenders) you will see white smoke from the exhaust. However, if the leak goes from the cylender to a water port where the coolant circulates through, basically compressed air gets into the cooling system and pushes the coolant out. A plugged radiator, heater core, or bad hose won't cause it. The radiator will do nothing but slow the coolant flow down and overheat the engine, the heater core will provide little to no heat in the vehicle, and a hose. Well it will leak or could collapse. If collapsed, based on what hose it is, it will do nothing more than stop the flow of coolant.

Let us know if you have questions in the future, and thanks for using 2carpros. Com.

Joe