2020 Sierra SLT A/C noise

[Sierra20-20]

I bought a 2020 Sierra SLT with close to no miles on it. Drove for about 5 days now and noticed a strange sound when the AC is on. Typical noise when the fan is on without AC. Then turn the AC on, I hear the compressor kick, cold air comes, and I hear a slight whining sound. Almost like when your turning an older car with power steering. It increases and decreases with accelerating RPM even when in park. Not ticking, clunking, just like a high pitch whining. A couple people sat in the truck and confirm hearing it but they are telling me that it sounds “normal”. I’m coming from a 2015 F150 which had no sound when the AC was running. I can only hear this strange sound when it’s on the lowest possible setting with the ac compressor running. I set an appointment for next week and it’s obviously covered under warranty but am I crazy? Is it supposed to sound Like that? Do GMC’s have more cabin noise than Ford? I feel like I just spent $60k on a truck and expect it to be quiet.. anyone notice the same with the newer GMC trucks? Any issues similar.. 

[2020HD]

Do you hear it when your at idle and no AC on? Alot of people have been hearing similar sound like that or rushing water sound at idle and once you give it gas it goes away. Then comes back when you get back down closer to a stop. Dealer told me it was normal. I dont know about that only time will tell but yours may be a different noise if its only when AC is on. Also mine is a 2020 Silverado 2500hd high country

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[blackbay2005]

My 2019 Sierra makes the exact same noise (whirring with rpm) when the AC is on.

I notice it from starting from a stop or backing up, but not at steady highway rpm.

Don't know if its normal or not.

Also after sitting in the hot sun, it takes a long time to cool down (half an hour plus)

[Sierra20-20]

Yeah, so, I’m assuming at this point that it’s normal. I jumped into another’s guys truck that was the same (other than his was AT4). He didn’t notice the sound until I pointed it out lol so Apparently it’s normal for this truck / style etc. it’s good to know I’m not the only one. I’m just trying to accept it and not let it bother me too much. In reality, I have my music on 99% of the time so if it’s a design flaw, it’s whatever. I’ll prob cancel my appointment and just bring it up during an oil change or something. Now knowing that I’m not the only one, I feel much better. Seems like we’re all just living with it lol let me know if there’s a solution though 

[Cesar Berbardo]

I have the same issue, but I drive a 2020 Silverado RST, but that whining that you all say is there. I already check other trucks, including GMC trucks because I assume al GM trucks use the same AC system, and there wasnt that sound. My local GM dealership already changed me the AC motor, or at least they told me they did, but there thaht annoying sound still there. As you said, some people had told me that is normal, even at the dealership they said it was normal, but they ended up changing that AC motor, but now they seemed skeptical about this.

[Kayla Ross]

I've also been having the same issue. 2020 Silverado RST 12000km. Didn't happen last year. Dealership says its normal and its because its under load...we've been having some really hot and humid days. Said to keep an eye on it. Won't lie...i'm not impressed considering its a 60k truck and its quite noisy. 

[Nestor Romero]

On 6/19/2020 at 12:34 AM, Sierra20-20 said:

I bought a 2020 Sierra SLT with close to no miles on it. Drove for about 5 days now and noticed a strange sound when the AC is on. Typical noise when the fan is on without AC. Then turn the AC on, I hear the compressor kick, cold air comes, and I hear a slight whining sound. Almost like when your turning an older car with power steering. It increases and decreases with accelerating RPM even when in park. Not ticking, clunking, just like a high pitch whining. A couple people sat in the truck and confirm hearing it but they are telling me that it sounds “normal”. I’m coming from a 2015 F150 which had no sound when the AC was running. I can only hear this strange sound when it’s on the lowest possible setting with the ac compressor running. I set an appointment for next week and it’s obviously covered under warranty but am I crazy? Is it supposed to sound Like that? Do GMC’s have more cabin noise than Ford? I feel like I just spent $60k on a truck and expect it to be quiet.. anyone notice the same with the newer GMC trucks? Any issues similar.. 

did you find a solution to this? What was causing the noise?

[Nestor Romero]

On 6/26/2021 at 9:23 AM, Kayla Ross said:

I've also been having the same issue. 2020 Silverado RST 12000km. Didn't happen last year. Dealership says its normal and its because its under load...we've been having some really hot and humid days. Said to keep an eye on it. Won't lie...i'm not impressed considering its a 60k truck and its quite noisy. 

Did you find a solution to this? What was causing the noise?

[Nestor Romero]

On 6/19/2020 at 10:00 AM, blackbay2005 said:

My 2019 Sierra makes the exact same noise (whirring with rpm) when the AC is on.

I notice it from starting from a stop or backing up, but not at steady highway rpm.

Don't know if its normal or not.

Also after sitting in the hot sun, it takes a long time to cool down (half an hour plus)

Dis you find a solution to this? What was causing the noise?