Whining/supercharger noise when RPM’s increase

Sierra Dan · September 13, 2019

Could be the oil pump.

This was a common noise on the earlier 14 and 15 K2 trucks.

Possibly alternator as well.

2019SierraAT4 · January 20, 2020

I have a 2019 GMC Sierra AT4 with 6.2 liter and 10 speed auto with 33,000 miles. It recently developed a loud whine that was tied to throttle input. The more throttle the louder it got. Took it to my local GMC dealer and they found it was a bad idler pulley. They replaced the pulley and the whine is gone.

Edited January 20, 2020 by 2019SierraAT4

ECGolfer04 · July 31, 2020

On 9/12/2019 at 10:46 PM, Aycock1987 said:

I am experiencing a noticeable whining noise when my RPM’s increase. It almost sounds like a supercharger. Curious to know if anyone else is experiencing this and know what it is. I tried posting a video but it wouldn’t let me attach.

Did they find your issue? I believe I may have the same noise. Slight wine, happens entire time while engine is running. Increases with RPMs, doesn't matter if AC is running or not. Ironically, I noticed it immediately after I had my transmission fluid change, which leads me to believe it could be trans pump? Or maybe Oil pump? I had both done on the at the same time. I dropped it off at the dealer but they cant seem to isolate it. Told them I'm not picking it up until its fixed as I am nearing the end of my powertrain warranty. Thanks.

jnissen · August 1, 2020

Likely wrong fluid used. The 10 speeds had a service bulletin out on the fluid if memory serves me. I’d verify level first (no dipstick so you will have to climb under truck). If ok then I’d change it anyway. When I do trans fluid I always do a 3X drain and fill. Between each change I run through the gears and ensure torque converter has had fluid flowing through it well. Then drain and repeat.

GM has a power flush machine they use at the dealer. I’d avoid those if you can. A friend of mine who runs a transmission rebuild shop claims they stir up stuff and long term you have more problems.

ECGolfer04 · August 1, 2020

42 minutes ago, jnissen said:

Likely wrong fluid used. The 10 speeds had a service bulletin out on the fluid if memory serves me. I’d verify level first (no dipstick so you will have to climb under truck). If ok then I’d change it anyway. When I do trans fluid I always do a 3X drain and fill. Between each change I run through the gears and ensure torque converter has had fluid flowing through it well. Then drain and repeat.

GM has a power flush machine they use at the dealer. I’d avoid those if you can. A friend of mine who runs a transmission rebuild shop claims they stir up stuff and long term you have more problems.

Dealer supposedly checked twice to make sure correct fluid was used? Is there a tsb on the correct fluid?

jnissen · August 1, 2020

I thought so but mostly was related to the 8 speed.

If dealer changed the fluid then I’d hold him responsible for the start of that noise.

Velocity12 · August 27, 2020

My truck (2019 Sierra, 5.3, 8 speed) started making a whining sound about 3 days ago. It’s coming from under the hood for sure. I can rev it and hear it and it does it when the truck is in gear. Sounds like it’s supercharged. It also seems like it’s getting louder as the days go by. I’m going to try to bring it in next week some time. Hopefully they can figure it out. I don’t have much faith in my local dealer.

EricTheRed · October 1, 2020

I got a 2020 6.2 Trail Boss that has an engine whine too. My wife and I both noticed it the other night.

Brian21477 · December 3, 2020

2020 LT Trail Boss 6.2L 10 Speed. I have the whine too. I only hear it at lower RPMs while accelerating from a stop between 25-35 mph then faintly goes away. Took to dealer at 1500 miles and they replaced the Stub Shaft on the front left wheel (this was a Bulletin for a noise only in 2wd that goes away in 4wd), didn’t solve the whining problem. 2100 miles, took it back for the whine and they replaced a bearing somewhere near the transmission pump. They had it for 2 weeks. When I drove it off the lot, whining noise was still there. I took it right back to dealer and they pretty much scratched their heads! Currently have 2800 miles on it and no impact no idea! What’s next? Lemon Law? Not sure if this will eventually turn into a recall or just a flat out safety issue that will either cause some failure while driving or just a lot more headaches to come. GM please figure this out!

Velocity12 · December 3, 2020

On 8/27/2020 at 3:38 PM, Velocity12 said:

My truck (2019 Sierra, 5.3, 8 speed) started making a whining sound about 3 days ago. It’s coming from under the hood for sure. I can rev it and hear it and it does it when the truck is in gear. Sounds like it’s supercharged. It also seems like it’s getting louder as the days go by. I’m going to try to bring it in next week some time. Hopefully they can figure it out. I don’t have much faith in my local dealer.

The dealer was able to fix mine, ended up being the idler pulley on the engine.

M1ck3y · December 3, 2020

Maybe trucks do take after their owners

Brian21477 · December 6, 2020

On 9/13/2019 at 1:57 PM, Wheelguy said:

Many odd noise complaints across several different topics (jingle jingle thread, squeaky belt/pulley thread, now this one). I realize that's nothing new, particularly with a first year new platform truck.

I work for a large supplier to GM in the powertrain segment and I've been told just this that GM Global Propulsion Systems (GPS - formerly called Powertrain or GMPT) is investigating some noises due to metal stampings, some are heat shields on what I believe is just the 6.2L. This may or may not be related to any of the above noise complaints/issues though I'm doubtful it's related to the jingle jingle since that seems to be pointing to the front axle stub shaft.

I know this isn't anything concrete or maybe not even worth posting. Just some info that may or may not put some owners at ease. No clue as to what specific components have been isolated by GM or where they might be, so please don't inquire further - I can't answer further because I simply don't know much more. I wish I could just call these guys up and give them symptoms and get questions answered but that would be frowned upon by my employer, I'm sure.

Hang in there, guys.

Has there ever been a known fix for the engine whine yet?

Edited December 6, 2020 by Brian21477
Didn’t finish typing

Brian21477 · December 6, 2020

On 9/13/2019 at 1:09 PM, Aycock1987 said:

I noticed the noise soon as I purchased the truck. I drove my dads 2019 (identical to mine) the other day and it didn't make the whining/supercharger noise that mine makes. I currently have 3k miles on mine

Noticed mine right after I bought too. Around 500 miles maybe. Two dealer visits with parts replaced and 2000 miles later the noise still remains. Irritating. Gloat all confidence in my local dealer.