Squeaky belt or pulley on 6.2 HC

[Bunker1]

On 6/10/2020 at 11:04 PM, RST-stan said:

So glad to hear Im not the only one. I don't have a HC, just a regular ol RST. I wonder why it only does it on the auto stop for me, but not cold starts or even warm starts for that matter. Im failing to see what is actually squeaking tho, is this an oil pressure issue to the valve train? 

 

[Bunker1]

The dealership changes the belt with no prevail.  I further looked into the squeaking when starting and low idil and found the noise was coming from below and  not the engine bay.  I’m thinking it may be the flywheel area. Considering It’s when starting it makes sense.  Like mentioned before, it’s embarrassing having purchased a new truck and having this issue sucks.

[Jav_eee]

The dealership changes the belt with no prevail.  I further looked into the squeaking when starting and low idil and found the noise was coming from below and  not the engine bay.  I’m thinking it may be the flywheel area. Considering It’s when starting it makes sense.  Like mentioned before, it’s embarrassing having purchased a new truck and having this issue sucks.

Nope. Look farther back. Under the drivers side front door. That’s where you’ll find it because it’s not the belt or motor. It’s a normal noise that ALL 6.2s make.


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[2017Z]

Any Updates on this?  I have a 2020 6.2 TB that does exactly this and like in the video posed by FishHuntRepeat.

 

Dealer said they cannot hear it or get it to repeat.  I think it is related to the Auto Start Stop.  If I turn it off after start up, it will go away quick.  Could this be something charging up?  Not sure how that Auto S/S functions or if it has a belt or compressor ran to it.  Cant see PIP5587 has changed from "Normal Noise"

[Bratbowtie]

2020 gmc 6.2 back in garage for 3rd time on the bird under the hood issue. Already had belt and alternator replaced,  than i got all 6.2s make that noise, now the noise is all the time, easy to duplicate,  i think it is 2 difference issues. service manager even started a new 6.2 for me and said GMC, said thats normal, that's a crock we all know that, i believe GM knows what it is but sales are good now and they dont care, my response was let's start 100 other trucks and see how many of them squeal,  Dodges dont ,Fords dont, Toyotas dont. it is very disappointing to be blown off ,I've been loyal to GM for over 40 years of driving but they dont care i guess, sad, sad sad,  im not going down with out a fight,  i want my truck fixed. Thsts all i want, not a brochure, tv ad, internet commercial,  mentioned,  squealing on start up, rants over, i dont think im the only one

[Jav_eee]

2020 gmc 6.2 back in garage for 3rd time on the bird under the hood issue. Already had belt and alternator replaced,  than i got all 6.2s make that noise, now the noise is all the time, easy to duplicate,  i think it is 2 difference issues. service manager even started a new 6.2 for me and said GMC, said thats normal, that's a crock we all know that, i believe GM knows what it is but sales are good now and they dont care, my response was let's start 100 other trucks and see how many of them squeal,  Dodges dont ,Fords dont, Toyotas dont. it is very disappointing to be blown off ,I've been loyal to GM for over 40 years of driving but they dont care i guess, sad, sad sad,  im not going down with out a fight,  i want my truck fixed. Thsts all i want, not a brochure, tv ad, internet commercial,  mentioned,  squealing on start up, rants over, i dont think im the only one

And you know for a fact it’s coming from under the hood?

My noise is coming from under the drivers door.



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[crowag2010]

Just bought a '21 AT4 with the 6.2 in January. Have about 2200 miles on it now, and I'm having the same issue. My truck came from the dealer with an upgraded exhaust and a K&N intake. It sounds like birds chirping/belt squealing. I really notice it when I'm coasting/slowing down and the truck downshifts around the 15mph mark. I can replicate it 95% of the time I would say. Very disappointed to hear this has been an issue that hasn't been addressed by GM! 

[TheChief]

2020 TB 6.2 10 speed. Same issue. 12,****** miles. Whining occurs during cold start or when truck has been sitting for a few hours or more. Whines for 20-30 secs, and under low rpm while driving.

 

Read all 7 pages of this thread. And from what I gather there doesn't appear to be a fix and it is considered normal for 6.2s.

 

Someone please correct me if I'm wrong. 

[Eastonm]

Q

Edited April 18, 2021 by Eastonm

[Eastonm]

https://youtu.be/p_FWk9lEPfs

 

The noise that made me take it in finally

[Moledigger2019]

19 lttb 5.3 8 speed has the same.

 

[Flyboygt]

Add me to the list of bird chirp. '21 TB 6.2L. i first noticed it at about 1700 miles on it. id say it happens on 90% of startups from sitting (not auto S/S). I will say that it is coming from the drivers side, under side is more pronounced than above the motor.

 

Someone previously mentioned possible problems as the DFM cylinder shutdown, has anyone tried using the Pulsar LT DFM delete to fix it? I have one on the way so I will report back if that resolves the issue.

i have an appointment to take it to the dealer, lets see what they say!

 

im also trying to understand what a "squeaky exhaust valve" is? i dont see how its possible to have that little oil in the valve train to cause a squeak/squeal and if so we would have a lot more bent valves and rods than the 1 listed above!

 

as for this being "normal" I would disagree. It didn't squeal at the dealership when I drove it so i would say that this is not "normal"

Edited May 28, 2021 by Flyboygt

[ODINAF]

I have a 2019 gmc sierra at4 5.3  and the dealership recently changed the harmonic balancer on mine under warranty and that fixed the squeaking/ chirping sound it was making 

[Flyboygt]

5 hours ago, ODINAF said:

I have a 2019 gmc sierra at4 5.3  and the dealership recently changed the harmonic balancer on mine under warranty and that fixed the squeaking/ chirping sound it was making 

 Great to know we are making progress!!!

 

Was your problem on startups or was it all the time?

 

im lost why it only happens on startup (cold starts and auto S/S) and then goes away after 30 ish seconds??

[ODINAF]

It would do it on startup pretty much every morning and then go away sometimes and sometimes it wouldn't. I figured it was maybe moisture from sitting over night but even on hot days after work it still would make the sound so I had a friend of mine who is a mechanic diagnosed it for me and told me to take it to dealer since I had warranty still n that they should fix it and they did. Took 2 days for them to fix it but now it's quiet like it's supposed to be,  love starting it in the morning and all I hear is my exhaust