2003 Pontiac Aztek Heater takes forever to heat up

  • 6 CYL
  • FWD
  • 100,000 MILES
For as long as I've have the aztek, which is a little over a year, the heater has taken a fairly long time to begin heating the car. No matter how long I start my car before beginning to drive it, it does not heat up unless I am driving over about 60 mph. In the case that it does actually heat up when I am going pretty fast, if I slow down or come to a stop at a light, the air blowing out of the car cools off pretty quickly. After doing some brief research into the problem online, it seems that there are other people who have the same problem with their pontiac Aztek as well. I'm beginning to wonder if it has a problem at all or if that's just the way it runs. Just looking for some answers before I take it to be looked at. Thanks!
Do you
have the same problem?
Thursday, October 30th, 2008 AT 12:33 PM

1 Reply


Well, let's check a couple of things. First you can go to Auto Zone or O'Reilly's and they can check to see if your car has any DTC codes for free. Make sure if it does and you don't fix it and you need to get back with us you tell us the code number and what they said the code meant. Also while there have them pull their tester out and for free they can check your battery, alternator and starter.

Next, are you sure you have the correct amount of antifreeze in the radiator. This is extremely important.

Next, does the truck operating temperature seem to run cool? It is possible with the number of miles you have it is the thermostat. It may be stuck open therefore never giving the fluid time to heat up. The thermostat should start to open about 188 degrees and be fully open at 206 degrees. Also it looks like you can get a thermostat that is a 195 degree or 180 degree. I would put the 195 degree on in. This means it will not open until the temp of the fluid is 195.

Are the heater hose lines warm or hot at all going into the firewall? If the one going in is hot and the one coming out is not, then most likely your heater core is blocked. In the attached pic the inlet hose, # 1, if it is really hot and the outlet hose, #3 is not, the core is blocked.


Also, your radiator cap. Check it out really good. I would replace it. It keeps the pressure balanced in your system

Check and try these things before you pay to have it looked at and get back with us.
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Thursday, October 30th, 2008 AT 3:30 PM

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