No heat in car..... [Archive] - Forum


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10-05-2004, 08:03 PM
My dad has a 99 Grand Am Se. He went to turn on the defrost today and it was only cool air. Not real cold but not warm to defrost. Then he went to turn on heat on floor and it was the same thing. Is there anything that anyone knows of that I might want to check first before taking it in. Could it possibly be the t-stat. I didn't know if that controls the heat or not. Thanks in advance for any replys.

10-05-2004, 08:18 PM
can you change the temp for anything or is it just the defrost?

10-06-2004, 08:22 AM
it doesn't matter how high you change the temp higher or lower nothing happens. Its in defrost and when you change it to blow in your face or on floor.

10-07-2004, 07:42 PM
ok today the heat kicked on and ran. my father said he had the same problem with the a/c this past year. Could it be that the controls are going bad? The controls that turn it up and down? Any insight would do me good. Thanks.

10-19-2004, 12:24 PM
i have a LIM that i have yet to fix, and my heat don't work either. is it possible with a low coolant level that the air wont be properly heated??

10-19-2004, 12:52 PM
Even with a Poched lower intake manifold Gasket you should still be able to get heat, unless the breach is so bad that it has dumped the entire contents of the cooling system into the engine. :doh:

I'm thinking 1 of 2 things.
Electrical: the Temp selector is not functioning
Mechanical: the Cooling system is air locked.

10-20-2004, 02:19 PM
it dumps my coolant pretty fast

10-20-2004, 04:32 PM
There is one basic reason not to get heat if the engine is up to temperature. No coolent flow through the heater core.

Either there is not enough coolent in the system or not enough flowing through the hoses due to blockage. Blockage could be gunk in the hoses, a bad heat valve that regulates the flow or a plugged heater core.

10-21-2004, 09:15 AM
i think you are right

10-22-2004, 07:44 AM
I would be guessing at a possible clogged or corroded heater core. Do you get any smell when your car is warm? Run your car for a while switch to heat, open the hood and also check for leakage around the firewall.