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post #1 of 9 (permalink) Old 12-12-2013, 04:48 PM Thread Starter
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Hvac Issue! Baffled!

My girls Hvac is having an issue thats even baffling the mechanic. I'll try to explain this as best I can.

Ok so the heat to the upper (face) vents doesn't work, here's what I do know


1) it CAN'T be the heater core, Heat blows to the feet and windscreen.

2) heat WILL NOT blow to the "face" vents.

the mechanic doesn't know what the hell is up, we took the headunit out and could see the arm moving that directs air flow physically moving, so thats not broken..

The mech. had deduced that the face vents are tying to blow hot AND cold air at the same time(resulting in well..not hot air), so he programmed the car to only blow hot air all the time (its winter) this is temporary... but still, why the hell would it only blow room temp air out the face vents and not hot air?

It's a 2006 SS if that matters


Last edited by StevoElsupremo; 12-12-2013 at 04:51 PM.
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post #2 of 9 (permalink) Old 12-13-2013, 06:07 AM
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Well your heater core has coolant that flows to it, ensure that your engine temp is reading on your DIC 189 degrees Fahrenheit. It flows from the engine block (hot) to the heater core allowing warm-hot air through the vents. You may also have a blend air door that is stuck and will not allow for heat to come through.

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post #3 of 9 (permalink) Old 12-13-2013, 06:22 AM Thread Starter
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I thought it might be the blend door, but apparently its trying to blow hot and cold at the same time. He programmed the car to ONLY blow the hot air. I checked the heat temp as well and its getting up to proper temps. Remember, the hot air WORKS, it just wont blow to those vents..

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post #4 of 9 (permalink) Old 12-13-2013, 06:54 AM
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Then it does sound like the blend air door. When its pointed up, it allows for air to travel from A/C unti to heater core fins, creating heat and exiting to the vents.

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Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille
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post #5 of 9 (permalink) Old 12-13-2013, 07:14 PM Thread Starter
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any easy way to see if the bled door is working? we pulled the headunit, and saw a mechanical arm. When we switched it from Foot to face to winscreen the level/arm thing appeared to be moving fine.

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post #6 of 9 (permalink) Old 12-14-2013, 03:56 AM
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maybe it has become detached before arm ?

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post #7 of 9 (permalink) Old 12-14-2013, 05:16 AM
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Or maybe the shaft broke like a lot them do.

---------- Post added at 09:08 AM ---------- Previous post was at 08:33 AM ----------

https://www.yourcobalt.com/forums/pro...alt-sport.html

---------- Post added at 09:16 AM ---------- Previous post was at 09:08 AM ----------

https://www.yourcobalt.com/forums/pro...no-heat-2.html

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post #8 of 9 (permalink) Old 12-14-2013, 05:42 AM
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Once the door is mechanically engaging or electrically (haven't seen it in person, but they use either or), it flows to the vents through a bunch of tubes and comes out your vents. If the shaft is broken, you may be able to replace that, but in most OEM HVAC's, the unit is an all in one set.

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Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille
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post #9 of 9 (permalink) Old 12-17-2013, 07:55 AM Thread Starter
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hmm, I'll have to look at this! thanks guys!

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