Normal L8T noises?

BuckWallace · October 27, 2023

I have a 2024 3500 AT4 with the 6.6L gas and have always noticed a whine/turbo-like noise from the engine under light throttle around 2000 RPMs while going around 35 mph. Multiple people riding with me have commented that it sounds like I have a turbo. Is this normal on these engines, or is it something I should look into?

Here's a short video with the sound starting a few seconds in (best heard with headphones):

https://youtube.com/shorts/dGi86ZnyCS0?si=dHAih65a33jOO18_

Edited October 27, 2023 by BuckWallace

the8rotor · October 27, 2023

Totally normal! At least one other thread on this as well.

CRApex · October 27, 2023

9 hours ago, BuckWallace said:

I have a 2024 3500 AT4 with the 6.6L gas and have always noticed a whine/turbo-like noise from the engine under light throttle around 2000 RPMs while going around 35 mph. Multiple people riding with me have commented that it sounds like I have a turbo. Is this normal on these engines, or is it something I should look into?

Here's a short video with the sound starting a few seconds in (best heard with headphones):

https://youtube.com/shorts/dGi86ZnyCS0?si=dHAih65a33jOO18_

I'm not sure if it's the same noise on yours but mine has, what I would call, a whine I can hear at idle and under acceleration. It drove me nuts at first and noticed it would go away when I turned off the A/C. I was told it was normal and actually don't even notice it anymore now that I have over 10k on the truck.

BuckWallace · October 27, 2023

1 hour ago, the8rotor said:

Totally normal! At least one other thread on this as well.

Good to know! I did some searching and couldn't find anything—do you happen to have a link to the thread?

MORSNO · October 28, 2023

It's probably caused when the fan clutch is engaged, it can create a turbo wind noise.

Dunn · November 28, 2023

noisey girls unlike 1500s......

BuckWallace · December 16, 2023

So I did some more scientific testing on this (duct taped my phone in the engine compartment and under the truck near the transmission), and I'm almost certain this noise is coming from the transmission. When the camera was in the engine compartment you can only faintly make out the noise at certain points, but when it's under the truck you can hear it clearly. It seems to happen most noticeably in 4th-6th gears under light load. In doing research, it seems like the 10L80 in the GM/Ford 1/2 tons make a similar noise and dealers are saying it's "characteristic" of the 10-speed. I'm not sure if the same would apply to the 10L1000 in the HDs. I don't know if this is just something I should live with or at least take to the dealer to document it and have them claim it's "normal", because the truck otherwise drives/shifts fine.

Targa · December 19, 2023

My 2024 2500 Silverado has the same whine.

switters · August 25

Hi all, I just bought a 2024 Silverado 2500 6.6 Allison gas with 11,000 miles. It's making a high-pitched whining sound at lower RPMs when accelerating/decelerating. It's hard to explain, but my wife and friend immediately noticed when they got in the truck.

Hard to say if it's the same noise the OP had—I know in my case, the sound is way less clear on the recording than it is in person. You can listen to mine here (it's most noticeable between 3-5 seconds).

Also, I went to the Chevy dealership yesterday and drove both a 2500 and 3500 with the Allison gas transmission. Neither sounded like my truck. They were both relatively quiet (for 3/4 and 1-ton trucks, at least) and smooth. This tells me the sound is not normal. It's so loud and irritating that I would not keep this truck if they can't fix it.

OP: did you ever figure out the source of the sound? Was the dealer able to diagnose and fix it?

Edited August 25 by Chris Kresser

GMCustomerService · August 26

On 8/25/2024 at 9:25 AM, Chris Kresser said:

Hi all, I just bought a 2024 Silverado 2500 6.6 Allison gas with 11,000 miles. It's making a high-pitched whining sound at lower RPMs when accelerating/decelerating. It's hard to explain, but my wife and friend immediately noticed when they got in the truck.

Hard to say if it's the same noise the OP had—I know in my case, the sound is way less clear on the recording than it is in person. You can listen to mine here (it's most noticeable between 3-5 seconds).

Also, I went to the Chevy dealership yesterday and drove both a 2500 and 3500 with the Allison gas transmission. Neither sounded like my truck. They were both relatively quiet (for 3/4 and 1-ton trucks, at least) and smooth. This tells me the sound is not normal. It's so loud and irritating that I would not keep this truck if they can't fix it.

OP: did you ever figure out the source of the sound? Was the dealer able to diagnose and fix it?

We regret to hear of this high-pitched noise concern you are having troubles with in your 2024 Silverado and would like to investigate further. To get started, please send us an email to [email protected]. Make sure to include your Username and Forum name in the subject line with additional details. We look forward to hearing from you.

BuckWallace · August 28

On 8/25/2024 at 6:25 AM, Chris Kresser said:

Hi all, I just bought a 2024 Silverado 2500 6.6 Allison gas with 11,000 miles. It's making a high-pitched whining sound at lower RPMs when accelerating/decelerating. It's hard to explain, but my wife and friend immediately noticed when they got in the truck.

Hard to say if it's the same noise the OP had—I know in my case, the sound is way less clear on the recording than it is in person. You can listen to mine here (it's most noticeable between 3-5 seconds).

Also, I went to the Chevy dealership yesterday and drove both a 2500 and 3500 with the Allison gas transmission. Neither sounded like my truck. They were both relatively quiet (for 3/4 and 1-ton trucks, at least) and smooth. This tells me the sound is not normal. It's so loud and irritating that I would not keep this truck if they can't fix it.

OP: did you ever figure out the source of the sound? Was the dealer able to diagnose and fix it?

My buddy's 2024 gasser makes the same noise and I've had a few other people tell me theirs does that as well, so I've just chalked it up to normal transmission noise. It drives and shifts fine, so I'm just not gonna let it bother me for now.

switters · August 31

Well, in my case, the noise was not normal. The service department called yesterday and said it's a major problem with the transmission. Apparently, there's a service bulletin out about it. Service has to open a claim and call GM next week, and GM will walk them through exactly what needs to be done.

I bought this as a pre-owned 2024 vehicle with 11k miles last Saturday. The truck had this issue when it was delivered to me, so they obviously missed it during the pre-sale inspection. It also had two recall services that hadn't been performed. The silver lining is the dealership may give me a new 2024 truck with similar specs for about the same price, because they know they messed up.

BuckWallace · August 31

3 hours ago, switters said:

Well, in my case, the noise was not normal. The service department called yesterday and said it's a major problem with the transmission. Apparently, there's a service bulletin out about it. Service has to open a claim and call GM next week, and GM will walk them through exactly what needs to be done.

I bought this as a pre-owned 2024 vehicle with 11k miles last Saturday. The truck had this issue when it was delivered to me, so they obviously missed it during the pre-sale inspection. It also had two recall services that hadn't been performed. The silver lining is the dealership may give me a new 2024 truck with similar specs for about the same price, because they know they messed up.

Sorry to hear. Sounds like the dealer will take care of you, so hopefully they follow through!

switters · August 31

They did! Sold me a NEW 2024 for only a little more than the pre-owned 2024 I bought with the transmission issue. All's well that ends well!

KellyMoore · November 8

On 8/31/2024 at 8:28 AM, switters said:

Well, in my case, the noise was not normal. The service department called yesterday and said it's a major problem with the transmission. Apparently, there's a service bulletin out about it. Service has to open a claim and call GM next week, and GM will walk them through exactly what needs to be done.

I bought this as a pre-owned 2024 vehicle with 11k miles last Saturday. The truck had this issue when it was delivered to me, so they obviously missed it during the pre-sale inspection. It also had two recall services that hadn't been performed. The silver lining is the dealership may give me a new 2024 truck with similar specs for about the same price, because they know they messed up.

I have one making that noise

I unbolted the converter and cranked it and the noise is still there