A/C Compressor Noise?

[96americanluxury]

Has anyone else noticed an electronic humming/whirring type noise on their cars, especially when stopped or at low RPMs (more noticeable at low speeds due to wind and road noise not drowning it out) with the HVAC set to Auto or with A/C on?

The noise is definitely compressor related as it will disappear when I turn the HVAC off, and won't return with just the fan on. It will only return when I purposely turn on the A/C or put the system to "Auto", i.e. the compressor kicks on.

I sort of noticed this noise since new, but didn't think much of it. Now I think the noise is getting louder. Certainly annoying, really buzzes in my ears while stopped.

I plan to test drive another Regal or Malibu with the 2.0t to compare as well as have my dealership check it out. Just wondering if anyone else has had a similar experience.

 

[NormT]

That is HVAC system but not the AC compressor as it shuts off also with the engine.

 

[96americanluxury]

Well I have the Range Technology stop start defeat device, so the engine never shuts off. And I can duplicate it while in park with the engine running as well.

 

[FavaBean]

Well I have the Range Technology stop start defeat device, so the engine never shuts off. And I can duplicate it while in park with the engine running as well

Great! Post a video w/sound.

 

[NormT]

The Regal will still prepare for ass but with Range Tech it won't succeed.

My TourX will run that HVAC pump when backing up in the garage and it continues after shutting the car for a few seconds.

The AC uses a magnetic clutch and will make a slight chrip sound qhen engaged but is only heard with windows down next to a curb or Jersey barrier to echo it inside.

 

[96americanluxury]

This noise can be heard in the cabin, and is audible anytime the A/C compressor is commanded on. Especially noticeable going from no HVAC on to front defrost on.

My dealership has confirmed it is compressor noise. Going to check the refrigerant charge and go from there.

 

[Discod]

Mine only makes that noise when I turn on the heater and auto-stop engages. I just turn up the stereo 😎

 

[574896]

Has anyone else noticed an electronic humming/whirring type noise on their cars, especially when stopped or at low RPMs (more noticeable at low speeds due to wind and road noise not drowning it out) with the HVAC set to Auto or with A/C on?

The noise is definitely compressor related as it will disappear when I turn the HVAC off, and won't return with just the fan on. It will only return when I purposely turn on the A/C or put the system to "Auto", i.e. the compressor kicks on.

I sort of noticed this noise since new, but didn't think much of it. Now I think the noise is getting louder. Certainly annoying, really buzzes in my ears while stopped.

I plan to test drive another Regal or Malibu with the 2.0t to compare as well as have my dealership check it out. Just wondering if anyone else has had a similar experience.

I'm having the same experience as you. Came on here to check if it's common before taking it in. I'll update when I do.

 

[96americanluxury]

I'm having the same experience as you. Came on here to check if it's common before taking it in. I'll update when I do.

So my dealership did replace the A/C compressor. Unfortunately it is making the same noise with the new compressor.

We had a dealer trade come in, a 2020 TourX optioned almost identically to mine. I tested this car and it makes the same exact noise, whirring electronic noise as soon as the compressor turns on that becomes more noticeable with RPMs, mainly 1500-2500.

I also checked a 2018, and it made a similar but less noticeable noise too.

At this point, I think it is either a poorly designed A/C compressor or I've heard the new R1234yf refrigerant is more dense than the older 134a and so it makes the system louder.

I know my A/C line is not rubbing against the bolt head on the engine near the air box. I plan to check the remaining A/C lines to see if anything is rubbing.

I also plan to compare the noise to a 2020 Malibu with the same 2.0T and 9 speed, since both cars are based on E2XX architecture.

 

[Jmlo96]

I can confirm my 2019 makes this noise as well. I have a hunch like some have mentioned above that this has to do with 1234yf (yf stands for your f.......). I'll leave the rest up to everyone's imagination, lol.

 

[96americanluxury]

So my dealer and I believe it actually is a resonance that isn't being damped properly in the A/C lines. Maybe too few mufflers? Technical assistance has advised to loosen all the bolts and lines, let everything settle, and reassess. We'll see what happens.

I have determined that at some point the A/C line style changed. 2018's and 2019's have a certain style, and 2020's have a different style. I haven't determined if any late 2019's have the more recent design.

I have also determined that the A/C line style on the 2018's and 2019's is very similar to that of the Chevrolet Malibu Premiers with the 2.0T.

I posted a video to the 9th gen Malibu facebook group, and one person replied that they experienced the same noise. She said their dealer found a loose A/C line; took three trips to get it figured out.

Does anyone know how to post a video to the forum? I've tried just about every way and format possible and can't seem to get it.

 

[Jmlo96]

So my dealer and I believe it actually is a resonance that isn't being damped properly in the A/C lines. Maybe too few mufflers? Technical assistance has advised to loosen all the bolts and lines, let everything settle, and reassess. We'll see what happens.

I have determined that at some point the A/C line style changed. 2018's and 2019's have a certain style, and 2020's have a different style. I haven't determined if any late 2019's have the more recent design.

I have also determined that the A/C line style on the 2018's and 2019's is very similar to that of the Chevrolet Malibu Premiers with the 2.0T.

I posted a video to the 9th gen Malibu facebook group, and one person replied that they experienced the same noise. She said their dealer found a loose A/C line; took three trips to get it figured out.

Does anyone know how to post a video to the forum? I've tried just about every way and format possible and can't seem to get it.

That is a very interesting find. Maybe you could upload the video to YouTube and post the link?

 

[BryanF]

I have a 2020 Sportback and it has the same annoying compressor whine.

 

[96americanluxury]

So my dealership and I believe the noise is A/C line related. The dealership has ordered new A/C lines and a new thermal expansion valve. Supposedly this has fixed a GMC Acadia which had the same noise.

I'll update once the parts are in and installed.

 

[96americanluxury]

Here is a video of the noise I am experiencing.

My dealership is still waiting on the new A/C lines and thermal expansion valve to come in.

 

[BryanF]

Here is a video of the noise I am experiencing.

My dealership is still waiting on the new A/C lines and thermal expansion valve to come in.

Yep, same sound as mine, but yours sounds louder. Keep us posted when the dealer gets done with it!

 

[96americanluxury]

Update everyone.

So the A/C compressor was replaced first many months ago and did not fix the noise.

At the recommendation of a field engineer, all of the A/C lines and the thermal expansion valve were replaced.

The new A/C lines did not come with the weird brass fitting that my original line and the 2020s have.

The new A/C lines and thermal expansion valve DID NOT fix the noise. If anything, the noise may be worse.

I have compared my car to 10+ other Regals, 2018, 2019, and 2020 models, as well as 2 Chevy Malibus with 2.0L, and they have all had the same noise to varying extents.

I truly believe this noise is just inherent to the design of the system unfortunately. I think the brass fitting was a stop gap to try and fix the issue. At the end of the day, my technician and I agree that another muffler most likely needs to be built into the system to alleviate the noise.

 

[BryanF]

Thanks for the update, guess I’ll just live with it 🤷🏼‍♂️

 

[94cruiser]

Can you p

The Regal will still prepare for ass but with Range Tech it won't succeed.

My TourX will run that HVAC pump when backing up in the garage and it continues after shutting the car for a few seconds.

The AC uses a magnetic clutch and will make a slight chrip sound qhen engaged but is only heard with windows down next to a curb or Jersey barrier to echo it inside.

Can you provide a video or audio?
I was under impression the pump noise at engine off or ASS was engine coolant pump noise.
I gad my ac system serviced and now mist of the time when the ac compressor is on I hear a noise..

 

[94cruiser]

Yesterday I heard it at idle and as it was raining I could not get a good vibe for it while driving.

Today on the drive in to work I can say that yes, that's what I'm experiencing.

Why did I not hear it before?
The first car I tested I was blown away how quiet it was, etc compared to my old car I replaced...
The second car I know I ran the fan on higher speed as it was a warm day
The car I ended up buying I test drove on a cooler day and maybe it already had the ac leak I took it in for...

So yeah, it totally sucks one has to bump up the fan to a higher speed or radio on to help muffle that noise.