The heater in my wife's car finally gave out today. At first when you turned it on, it sounded like something was rubbing. After about two months, the rubbing sounded terrible, and she didn't let me know until it finally gave out. Any ideas on where the problem lies, or how to fix it? We have already put way too much money into this car for the kind of shape it is in, and I don't really want to spend an extra $500 dollars to have it looked at.