Mechanics

DOESN'T BLOW HOT AIR

1997 Buick Park Avenue

Heater problem
1997 Buick Park Avenue 6 cyl Front Wheel Drive Automatic 70000 miles

I recently bought this car. A/C was not really cold so I recharged freon and A/C seems to work well now. But with cold weather, I find that there is no heat coming from vents. Only cold air. Fan works at all speeds and dash controls change airflow directions normally from floor to middle to windshield. Air flow is great and variable by dash controls. Problem is the air is not heated even after the engine is 200 deg F. All else seems well. Visual inspection tells me nothing because I don't really know where heater valves, etc. Are located. Everything under the hood seems fine at first glance. Idon't know what or where to check.
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Arepa
November 1, 2010.




Test the thermostat, heater core if its clogged-up and check the air blend door could be stuck in the cold position

Rasmataz
Nov 1, 2010.
Thanks rasmataz. I don't think it's the thermostat but I will double-check. But how do I check the air blend door? Is that different from the flaps that change the airflow direction from windshield to floor?

Tiny
Arepa
Nov 1, 2010.
Thanks again rasmataz! I did some checking and have this info. I think the thermostat is good because the top radiator hose gets hot and the engine temp. Climbs to about 210+ degrees F. I am suspicious of a clogged heater core because only the top heater hose gets hot. The other hose doesn't get hot at all. There is no leak in the heater core as verified by looking up under the dash for leaking coolant. I have been reading up and I think flushing the h. Core should be the 1st step because it is easy and cheap. Does that sound reasonable to you rasmataz? Also, can I assume that the hot heater hose is the inlet to the h. Core?
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Tiny
Arepa
Nov 1, 2010.
The hose don't matter it suppose to be the same temp-flush it out and see what happens

Rasmataz
Nov 1, 2010.
Flushing the heater core did the trick! I just used plain water. I hooked up a garden hose to my washing machine hot water connection and used hot water to flush the core. I flushed in both directions several times. I am surprised at how little debris it took to stop the heater core completely up! I wouldn't be surprised if I need to flush it again since there may still be debris in the rest of the system. Thanks for your help!

Tiny
Arepa
Nov 2, 2010.

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