The GXP seems to warm up perfectly, but after about a half an hour of driving it will start to feel cool in the car. The engine temp guage reads normal and I usually have the auto climate set on manual at 90 degrees. It actually cycles from warm to cool and back to warm. I've never had it do this before. A couple of times the blower seemed to cut out and then back on. Any clues?

Its normal.

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2012 CTS-V Coupe, 4k miles and counting.



2005 Bonneville GXP, 200k and SOLD!

I cant say if its normal as I havent had mine but a week. However I would check to make sure your coolant level is all the way full in the radiator.

Brian

IF you are getting heat out of it when you want heat, then I'm thinking this is fine. Say if you set it at 80*, it's just adjusting automatically to maintain that 80*. One minute it may seem as though you're getting hot air, then a minute or two later, almost cold air by comparison.

The first thing I would check, is set it to 90* (the max) and verify that you get sustained hot air blowing out. IF this is not the case, three areas I would start looking at.

1) Thermostat first
2) the actuating mechanism on the blower housing that opens/closes airflow (typically how it regulates that auto air temp is by closing/opening a door)
3) Headunit.

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Retired Bonneville Owner and former GM Tech:
2004 Pontiac Bonneville GXP: Black/Ebony *SOLD*

Summer Toys: Combined 827 RWHP / 877lb/ft RWTQ
2004 Pontiac GTO: Impulse Blue Metallic/Black/M6: lots 'o mods, 415 RWHP / 405lb/ft RWTQ!
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