Anonymous asked in Cars & TransportationMaintenance & Repairs · 1 month ago

Why is my car heat not working?

I have a 2001 Monte Carlo. The heat blows, but it isn't strong enough to heat the inside of the car. The thermostat is new. The coolant is at normal level. The system has also been flushed (by a professional) and circulates very well. I also haven't noticed any air in the cooling system. The heat coming out is extremely warm and the flaps in the plenum are opening and closing properly. The fan also sounds like it's working correctly. What should I be checking to fix this issue? I wouldn't think it was the fan by the way it sounds, but that's the only thing I can think could be causing this issue since warm air is coming out but not circulating well inside the car. I'm not very savvy when it comes to heat and air issues with cars so any advice would be awesome. 

7 Answers

  • 1 month ago

    When they flushed the cooling system did they take the heater core hoses off and blast water through the heater core in both directions? That needs to be done to get the DexCool that plugs up the heater core out of the heater core.

    Source(s): Mitsubishi Master Tech
  • 1 month ago

    Probably a partially plugged heater core.

  • Anonymous
    1 month ago

    Replace the cabin filter if it has one.  Check for a bad blend door actuator.  Without using heat, check if the blower is working as advertised.  Blower motor could be shot.

  • Jay P
    Lv 7
    1 month ago

    Not sure if your vehicle has a cabin air filter but if it does, check that to make sure it's not plugged.  If it is dirty/plugged, it will definitely hinder air flow.

  • How do you think about the answers? You can sign in to vote the answer.
  • 1 month ago

    If the heater is producing heat then the fault must be with the circulation system. Before pulling all that out check the inlet filters.

  • 1 month ago

    Has the cabin air filter been cleaned or replaced in the last few years?

    That's where the AC/heat system draws outside air in to the system. If it's clogged up, that will restrict airflow.

    This is what it looks like:

    And this shows the location of the filter for your car:

  • Anonymous
    1 month ago

    Going with what you said here, It may have been replaced and new but I would go back and check the thermostat for starters. New parts can fail sometimes. 

Still have questions? Get your answers by asking now.