Does it just blow cold or lukewarm air? Have you checked the blend door for proper operation? It could be stuck, or the blend door actuator may be faulty.
Or you may just have an air pocket in the cooling system which has settled in the heater core. Sometimes they can be tricky to purge. It may help to safely raise the front of the vehicle while "burping" the system.
Thursday, October 13th, 2011 AT 11:05 PM