2003 Chevy Monte Carlo 6 cyl Front Wheel Drive Automatic 115000 miles
I noticed that my car was blowing cold air so I instantly thought the thermastat was defective. Upon opening the hood I noticed the upper hose from the radiator to the thermastat was full. I then changed the thermastat thinking that was the solution. I bleed the system to get rid of any air. The heat was warmer but not hot after being on for a half hour or so. So with that being said I was wondering what possible reasons are there for no heat and possible solutions.
Is your car dual climate control? It sounds like it may be the actuators are not working.
Although I am not 100% sure if your car is vacuum operated or electronically operated. Meaning that when you change the dials of your climate control panel from say hot to cold or from dash vents to floor vents, they are operated by engine vacuum or electronically. I will assume they are electronically operated.
When you are not getting hot air from the dash it is usually because the actuators are not functioning. There are doors in the ducts that are controlled by little motors. The question is why aren't they working. Maybe the actuators themselves are bad or the control panel itself is bad. It is kind of hard to answer without knowing if your car is dual climate control or not. If it is does the heat work on either side or does it blow cold on both sides? Do all the vents work when you change positions from vents to dash to floor? Can you give more info?