2003 Park Avenue Heater Does Not Work Properly

2003 Buick Park Avenue. 3.8 V6 engine.
Question: The heater doesn't always put out heat.. I replaced the Thermostat. The old one appeared o.k. , but I replaced it anyway...Example Backed out of garage to go to a class luncheon, drove 2 miles to pick up my lady.. I let the car run ,went in & got her ,came out & drove to the luncheon approx 1 mile... Shut the car off, went to luncheon ,came out 2 hours later & started car .. Within 5 min the heat was pouring out.. This has happened several times.. The Dealer can't find anything wrong... Can You HELP me ??

Answer: If you have gotten the car up to operating temperature and the heat is on, it should blow warm air. Different driving circumstances can lead to different ways the HVAC system acts. Outside temperature, driving style, cold start up, etc, all will differ in how long it takes to produce heat in the car. If the car is hot and you have no heat, you could have a few possible causes for that. The thermostat could be sticking, even if it is new. You could have an electrical problem with the HVAC control head, or the temperature door actuator.

If either of those have a problem, it could blow cold air when you want it on heat. You may also have a partially clogged heater core, radiator, or both. You may want to try a coolant flush for starters and possibly another thermostat. That would be the easiest thing to do first.


Please login to comment

Comments (7)
   ---Subscribe To Your Comment   

  • Guest - Larry Harrington

    I recently bought a 2003 park avenue, from the original owner and love it! It only has, now 30,000 miles! It's in amazing condition with only 2 problems. First, the heater does not get hot, just cool air. At first it was great all around, then just got warm on the passenger front dash. The radiator is full and the a/c does work at all points. the second problem is with the door lock buttons, in both doors are pushed in the panel, but do work.

  • Guest - donna williams

    My 1996 Buick Park Avenue will not blow air or heat through the vents. It only blows on the windshield or floor. What part will fix that problem?

  • Guest - TechHead

    In reply to: Guest - donna williams

    This sounds like a vacuum problem. Engine vacuum is used to control the direction of airflow. With no vacuum to the system, it defaults to the windshield and floor. Need to check for vacuum under the passenger side of the dash at purple hose coming from the engine comprtment. If there is none, then go into the engine and follow that hose to its source and look for the hose to be broken or leaking.

  • Guest - Jack Ward

    I forgot to mention that all of the hoses were very hot. I could not hold on to them.. If heater core is blocked or if it's the temperature door actuator or also the HVAC control head, where are all of these and how do I go about replacing them if one or all of them need???<br />Thanks<br />Jack

  • Guest - Tech

    In reply to: Guest - Jack Ward

    If all the hoses were hot, and still no hot air from vents, then either a restriction in the heater core, or temperature actuator motor. Both of these are inside the dash. One temperature motor on the drivers side, the other on the passenger side. They don't usually fail at the same time, so check to see if one side is hot and the other side cool or cold. If it is the heter core, it is in the center of the dash. The console, lower dash panels, and duct work would need to be removed. Try a heater core backflush first.

  • Guest - Jack Ward

    In reply to: Guest - Tech

    The information is great. If I need to get into the dash, How do I go about that? Is there a picture or instructions of how to remove the dash or parts of it? I don't see any screws to start that process. I can use all the help or information that you will supply..<br />Thanks<br />Jack

  • Guest - Tech

    In reply to: Guest - Jack Ward

    The information is great. If I need to get into the dash, how do I go about that. Is there a picture or instructions of how to remove the dash or parts of it ? I don't see any screws to start that process. I can use all the help or information that you will supply..<br />Thanks<br />Jack
    <br />Sorry, don't have diagram for dash. You must get a mechanic to confirm a possible temperature door motor or heater core problem before just replacing it.