2017 Yukon Denali A/C intermitent

[Havasubum]

Hello

I'm having trouble with the A/C in my 2017 Denali.  I've already had the condenser replaced last year.  I just took a trip to AZ, and A/C would not put out cold air while on auto at 72 degrees.  When starting the car on a hot day, the A/C fan would not blow full blast.  In fact, I received a phone call and the fan didn't have to slow down like it normally does on a a hot day.  During the drive back to CA, the air started working better.  The dealer says the system is full of freon and can't recreate the problem.  They called GM HQ and was not able to get help from them.  Do you have any ideas?

 

Thanks

Jerry

[Justin101714]

Is this system primarily used on Auto mode?


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[Havasubum]

Yes, I've left in on auto/72 degrees since I bought it new.  I tried manually setting in on Lo when it was acting up.  It didn't help.

[Justin101714]

The auto for these trucks sucks....I’ve never been able to find a good medium in temperature either. I’ve had it set on 72 before and it feels like straight heat. Then other times it feels like it should or cooler. I think it’s a software issue that GM engineers haven’t really addressed yet. Especially since it affects all of the new style HVAC systems not just the trucks.


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[Havasubum]

I agree.  However, it has been working up to this point, and wouldn't work on manual either.

 

Thanks for the feedback

[Jsdirt]

From your description, you could have an issue with the cooling fans. That will definitely cause poor cooling, especially at slow speeds or in traffic. The condenser needs to be constantly shedding heat in order for the evaporator to get, and remain cold.

[silveradosid]

check the water drain from the heater box if it is plugged you can have freezing moisture on the evaporator which will reduce air flow and cooling

[Havasubum]

Hello everyone

 

I'm in Arizona, and it's been very hot the last week.  My a/c doesn't work well until I'm driving on the highway where air can circulate over the condenser.  Around town the a/c air varies from sort of cool to warm even with the recirculation activated.  According to the dealer this is a common problem with the new R1234yf refrigerant.  For those of you who watch Scotty Kilmer, he just published a YouTube video about how crappy it is.  Not only that R1234yf is highly combustable.  Can you say engine fires?

[Tahoe02]

I disagree as I live in Florida and drive a 2017 Chevy Tahoe and mine works great. You may be a little low on Freon and make sure you don't have a condenser leak which is a known problem and the warranty on 2015-2017 models have been extended to 60,000 miles because of this issue.

[Havasubum]

Condenser changed and freon full

[Tahoe02]

I would go drive another one like yours and see if it cools better. If it cools better then I would find a different Dealer.

[txab]

 

I've not had this issue on any of our trucks and it's been in the low 100's

 

You neglected to mention that the replacement condenser was not a GM part. This from your other thread. This is where I'd focus attention for starters. Did you have this issue prior to changing the condenser?

 

If you're anywhere near Scottsdale, I'd let Arizona Mobil Air give you an opinion on it

Edited June 23, 2018 by txab