My corvette is a great car but just a few days ago I turned on the heat and there was nothing. I have been looking around for coolent leaks and have spotted one near the passenger fire wall. Another thing my car is doing is the temp guage is going up when the car is at a stop but then goes back down when I start driveing again. There is a coolent smell in the car sometimes and once in a while the windsheild fogs. Could this be a faulty heater core?[/B]
You seem to have answered your own question.
My guess is that with the leak your level is down which will cause the warm-up at idle and when you start moving the water curculates faster and cools things down a bit. Change heater core and get system filled back up and I think your problems will be taken care of. Happy wrenching : D