17 Denali AC / Fan noise

[GMC_nolonger]

My first post never addressed one of the issues I'm having (I thought it was done) so I started a new thread...

2017 Denali XL ~10k mi

Whenever the climate control is on, AC or not (I think the AC runs even on heat, etc.) There is a noise that sounds like a old car when the AC clutch first starts and you hear it building pressure, except this is a constant noise that changes pitch with the engine RPM, when climate control is switched to off, it immediately goes away. Sound comes from the passenger foot area.

I first thought it was a bad fan or the ground was improper, something along those lines.

Took it to GMC dealer and they immediately replaced the "AC system" what I was told, turns out it was the compressor, and it made some sense to me that could be the cause. Didn't fix it. Took it back, they said they must of got a bad compressor, replaced it again. Didn't fix it, they knew it, told to bring it back when they get a new fan in. Replaced the fan, still didn't fix it but they gave it back and said "you should be good now".

Anyone had a noise like this, is this normal? I would think I was just hearing things except even the dealer spent a lot of money trying to fix it, I was assuming they would tell me they couldn't hear it, but at least they could and tried...Other than that the dealer/ service writer is horrible to deal with, and denied other issues that were obvious, so its a bit strange.

thanks!

 

[sickk23]

My AC makes a howling noise especially when you let off the pedal. It’s very annoying.

 

[GMC_nolonger]

My AC makes a howling noise especially when you let off the pedal. It’s very annoying.

hmm....I would say I hear it more when the rpm is going downward too...If I never heard the sound it probably wouldn't bother me but now it all I hear

 

[Tahoe14]

If you are having other issues that are not being addressed as you indicated along with this one then file a Lemon Law case and see how fast they want to fix your truck. You could also reach out to GM and have your case documented or try another Dealer.

 

[sickk23]

hmm....I would say I hear it more when the rpm is going downward too...If I never heard the sound it probably wouldn't bother me but now it all I hear

Does it come from behind the passenger side dash too? The sound I hear absolutely annoys me, especially if I’m riding shotgun and not driving.

 

[GMC_nolonger]

Does it come from behind the passenger side dash too? The sound I hear absolutely annoys me, especially if I’m riding shotgun and not driving.

Yes, it sounds like its at or near the firewall. I hear it a lot more in the passenger seat. What year is your rig?

 

[Tahoe14]

You may want to do a Google search as I saw a post on a chevy truck forum. The owner put dum-dum on the AC line at the firewall after several attempts to fix the issue at the Dealer.. May be worth a try.

 

[sickk23]

Yes, it sounds like its at or near the firewall. I hear it a lot more in the passenger seat. What year is your rig?

2018 Suburban Premier

 

[GMC_nolonger]

You may want to do a Google search as I saw a post on a chevy truck forum. The owner put dum-dum on the AC line at the firewall after several attempts to fix the issue at the Dealer.. May be worth a try.

Thanks, I searched and found that post, with a picture. I'll have to see if I can pinpoint the noise to that location and give it a try. Seems they were having the same issue with the truck, and dealer tried the same things to fix it but couldn't .... and then they fixed it with a little trip to home depot, kind of funny. thanks for the heads up

 

[Tahoe14]

Your welcome and I hope it is the fix you are looking for.