what is causing my heater to not send out hot air on 2003 Chevrolet Malibu

lately it has not been giving off warm air, sometimes after driving for an extended time period it will be slightly warm, but cools off when the fan is run.

by in Portland, OR on April 02, 2010
1 answer
ANSWER by , April 03, 2010
This problem could be a result in a faulty heater core.