Mercury Repair Questions? Ask a Mechanic for Answers ASAP
Is the engine running normally otherwise?
Any misfires or other issues
What is happening is as it loses the engine coolant an air pocket will form in the heater core. This will cause the loss of heat, but also cause the car to try to overheat.
What you really need to do here is try to determine where the leak is. To do this, I suggest a pressure test. Basically it's like a bike tire pump for the cooling system. You pump up the cooling system and it usually will force the coolant out so you can determine what needs repairing.
This is really where you have to start with this so that you can repair the leak, bleed off the cooling system and get your heat back. Sorry for the delay in my response.
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