In order to tell if a heater core is going bad, look for the windows and windshield to fog up whenever the car is started. Learn about how wet carpet and the smell of mildew can indicate a bad heater core with help from an automotive technology professor in this free video on bad heater cores.

Expert: Bob Ricewasser
Bio: Bob Ricewasser is a former automotive technology professor, and an avid car collector.
Filmmaker: Nathan Boehme