2023 Tahoe/Squealing at low speeds

[Deuce16GMCs]

Tahoe Squealing 2min video

Check this video out. Listen at the time stamps:

:28
:51
1:00
1:12
1:25
1:36
1:44
2:07
2:14

It's moderate when driving, very light when accelerating, and very loud when breaking.

I sorry about the wind noise. There's no other way to record this.

 

[Geotrash]

Tahoe Squealing 2min video

Check this video out. Listen at the time stamps:

:28
:51
1:00
1:12
1:25
1:36
1:44
2:07
2:14

It's moderate when driving, very light when accelerating, and very loud when breaking.

I sorry about the wind noise. There's no other way to record this.

Sounds to my ear that it's related to the downshifting of the transmission and tracks the engine RPMs for the second or two that it occurs. I suspect something in the bell housing. Almost sounds like when the starter return spring fails and the starter gear touches the flywheel teeth every now and then.

 

[Deuce16GMCs]

Sounds to my ear that it's related to the downshifting of the transmission and tracks the engine RPMs for the second or two that it occurs. I suspect something in the bell housing. Almost sounds like when the starter return spring fails and the starter gear touches the flywheel teeth every now and then.

It's loudest when braking, but I do hear it when shifting and sometimes hear it turning, or on bumpy roads.

As of few days ago I could hear it on the highway faintly.

It's a major pain. I'm usually pretty good about pinpointing the location or cause of an automotive problem, but this time I'm baffled.

Sometimes it sounds like a suspension squeak. Other times it sounds like a serpentine belt squealing. Other times it sound like birds chirping.

It at the dealership. Been there for 3 days and no calls or updates. The whole servicing with Chevy has been a nightmare.

 

[Deuce16GMCs]

Got the truck back. They said the squealing is perfectly normal. Despite the fact that no other Tahoe suburban Yukon Escalade makes the same noise. I despise Chevy service This was a utter complete mistake.

 

[Deuce16GMCs]

Got the truck back.

There was TSB for the 2015 squealing from the V4/V8 activation, and few members with 2015-2017 has complaints about squeaking squealing when down shifting and stopping.

I've been driving in L9 since yesterday and the squealing when stopping and on the highway is gone. Actually the truck is pretty smooth.

So I guess this may be tied to the Active Cylinder Management.

Question is why is my truck is doing it and not any other one I e seen or driven?

 

[Deuce16GMCs]

So for anyone who following or wants to know. Here what I have so far.

If you have a 6.2L 2023

After a week at the dealership Chevy/GMC/Cadillac combo, the tech heard the sound and could easily reproduce it the squeal. They also confirmed that the squealing is gone with the truck in L9 mode which deactivates the DFM.

They couldn't identify the location of the squealing while on the lift since truck doesn't do it when it's not under load.

They got the tech like involved. Tech like told them to take another 6.2L 2023 on test drive. The dealer had a Escalade on the lot with 100 miles on the odometer. They drove it and reported back that the squealing was also present on the Escalade.

The tech line deemed it a feature of the truck and no repair was authorized. The tech like also said that GM made changes to the programming of the DFM for the 2023 model years. What changes, who knows.

Today, I went to a different Chevy dealer that had a new 2023 Premier with a 6.2L on the lot with 12 miles on the odometer.

I drove it and it ALSO squealing. The dealer will get another 6.2L in a week. I'll drive that one as well.

I have not driven a 2023 5.3L, but it appears that if you have a 2023 6.2L, the squealing is normal.

If someone else has a 2023 6.2L and could drive with their driver's window down and verify if they are also getting the squealing when slowing down, I'd appreciate it.

1) If you smoothly drive up to 25-30 (causing the truck to switch to v4) and slow down gradually to a stop, when the truck slows to the near stopping point, the engine will switch back to v8 and the squealing can be heard.

2) If you cruising at 30-40 smoothly with little torque on the engine, the truck will operate at v4. If you tap the gas quickly (causing a shift to v8) you can hear squealing.

3) On could start up, you can hear the sealing from the engine for a minute until the engine revs back down and then it goes away.

 

[GoNoGo]

Will 6.2 cylinder de-activation occur when dash button is D and slower rural roads don't let tranny shift into 10th.. only gears 1-9 ?

I see that forcing console (dash) button into L and choosing 9 then cylinder de-activation won't occur.. but is the results the same if I never drive interstates or long-flat 4lane highways ?

 

[Deuce16GMCs]

Will 6.2 cylinder de-activation occur when dash button is D and slower rural roads don't let tranny shift into 10th.. only gears 1-9 ?

I see that forcing console (dash) button into L and choosing 9 then cylinder de-activation won't occur.. but is the results the same if I never drive interstates or long-flat 4lane highways ?

No. With DFM/Dynamic Fuel Management (2021-2023), the car deactivates 1-4 randomly depending on need. Unlike the old AFM that deactivated all 4 cylinders on the bank.

Because DFM can deactivate 1, 2, 3, or 4 cylinders, the system is always operational. Which means driving 15-20 miles an hour around a neighborhood, steady cruising at 35 mph, ridong with no load at 72 on the highway, etc...can all engage the DFM. You don't need to enter 10th gear.

L9 just tells the truck you want full torque all the time which keeps the DFM inactive and doesn't allow you to go past 9th gear.

So as right now, there's no way to trun off DFM without being in L9.

On a side note, there's an entire thread on the gmtruck forum of folks with 21-23 Silverados and Sierras with 6.2L who all have the the squeal.

Here's video of a Silverado Trail Boss 22 with the squeal coming to a stop.

 

[GoNoGo]

I'm very fortunate to never hearing the squeal in my 6.2 suburban and I am VERY attentive to all sounds and noises.. especially since I never listen to radio and don't carry passengers or pets. I enjoy listening to the vehicle, wind and road noise

 

[Deuce16GMCs]

I'm very fortunate to never hearing the squeal in my 6.2 suburban and I am VERY attentive to all sounds and noises.. especially since I never listen to radio and don't carry passengers or pets. I enjoy listening to the vehicle, wind and road noise



Have you driven with only the driver's window down and driven conservatively up to 25-30 and slow down to a stop?



Now that GM is admitting it and saying it's all 6.2's, I'd be surprised if it's not there.



But I ask because it gives us hope if every single one doesn't do it.