The Heater on my Malibu works sometimes if I do not turn fan on to high sometimes it doesnt work at all , Water is flowing thru the heater core there is no leaks .. I recently replaced Head gaskets and it works good but it didnt make any difference to heater
Cars & Trucks - Chevrolet - Malibu - 2003 Chevrolet Malibu
Answers & Comments
Sounds like your thermostat is stuck open.
Does the car have a water temp gauge or a light. ?
If only a light let the car run for about 10 mins and feel the radiator hoses. They should be good and warm. if not I'd change the thermostat