chirping noise ,still not addressed

[Transient]

I have this irritation too. 6.2 Trail Boss. Definitely not an exhaust issue since I have the GM Performance exhaust.

Sent from my SM-N960U using Tapatalk

[Bratbowtie]

I have been in on  a couple of these  sites, and my truck in 2 garages for total of 25 days ,they all do that, is all i got, has anyone have a real cause and cure, i would like to know,  i cant find it anywhere on the brochure that says annoying start u noise is normal when i bought my truck, GM and the deal must have forgot to put that in, 

[Bratbowtie]

Heres another update,  took my squealing 6.2 on a weekend trip, now its starting to squeak and squeal while driving and put under a load, really noticeable like between buildings,  accelerating down a ramp. And even when setting idling and give it a little gas, this is embarrassing and its not normal, has anyone had any help at all from GM, 

[Bratbowtie]

On 4/12/2019 at 4:49 PM, K455 said:

I am glad I am not the only one noticing this, it is not a major damaging sound I am thinking it may be the exhaust manifold getting hot.Ever notice when you shut your bike off Harley etc.. and hear the exhaust clicking. I wonder,I really do not think it is major,but It is not a tap,tick,slap, CLICK I say only on cold start idle and stops at 500 rpms when idle comes down or soon after.It just may be the manifold expanding because new.I have to say this Trail boss rides plush for what it is,I seen a post where a female was complaining about the ride,I disagree.

I am glad My OCD is not alone.

Keith

 

[Bratbowtie]

Has anyone bought a 2021 with 6.2, do they squeal  like 2019 and 2020s, 

[Bratbowtie]

Been in the garage for 3rd time. Over 2 weeks again, sent email to service manager buy back or lemon law. its been in the garage for 3 tries to repair same problem ,been in garage over 38 days and counting, truck has around 4 thousand miles,  less than a year old (2020) i think it is in the lemon law perimeters, or give me my money back,  I bet i can find one that dosent sound like a chirping POS, 

[Pinnacle]

On 4/2/2019 at 7:11 PM, OnTheReel said:

Just put a cat-back on it and be done! Even if they do replace it, it will make noise again before too long. 

Yup, always have some noise from the exhaust.  Thats the best way t go.

[Transient]

Thursday I noticed my belt squeaking intermittently while driving a rough paved road at 35mph. My windows were down, and I was the only car in the area. Shortly after I threw CEL I had OnStar email me a diagnostic report. The error code is P25A2. In case you can't see the attached pic, it says:

 

 

The Engine and Transmission System is not performing as expected. An issue has been detected in the Engine Electrical System, including the Charging and Starting System that monitors and controls the engine starting system and 12V battery charging system. If the charge system light stays on, or comes on while driving, there may be a problem with the electrical charging system. Driving while this light is on could drain the battery. If a short distance must be driven with the light on, be sure to turn off all accessories, such as the radio and air conditioner

 

I wonder if the squeak is the alternator pulley.

 

Sent from my SM-N960U using Tapatalk

 

 

 

[2021TrailbossLTMA]

On 10/13/2020 at 4:37 PM, Bratbowtie said:

Has anyone bought a 2021 with 6.2, do they squeal  like 2019 and 2020s, 

I have a new 2021 its been doing this from day 1.

 

I had the muffler deleted along with the adaptive exhaust valve.  Its still doing it.

 

800 miles and its going in for them to look at.  Funny thing is I brought it to one dealer and they said they heard it I took them on a test drive but when I spoke to the shop foreman he told me he couldnt touch it because the first thing they do is trouble shoot as it could be the adaptive exhaust value as when they are not operating properly that noise can happen.....uhhhhhhhhh I dont have one!

 

They literally wanted me to have the factory muffler welded back in so they could check the flapper...I couldnt stop laughing like I get it its easier to have something back to factory to diagnose but you think it could be the flapper when its not even installed on the car anymore? 

 

Another dealer is going to look at it.  For me it happens a little upon start up but mainly when im coming to a stop if I have the windows down right before I stop moving it sounds like the engine is shifting from 4 cylinder mode to 8 and right when that happens it chirps like a squeaky belt then at idle it goes away.  It can also happen if im cruising at a low speed and it goes to transition back to 8 I can sometimes hear it very slightly.

 

Again not sure if this is the same issue everyone else has had but thats what im facing.  Luckily the other dealer said they wont ask me to weld the muffler back in unless they cant figure out any other way it could be making the noise so it would be a last resort.

 

Will try and update again here with what i find.

[Transient]

When the dealership looked at my belt they told me they found a TSB to address this issue. The fix was to apply some sort of powder. It didn't fix the problem. I've had my brother take a look. He's a diesel mechanic, and works on everything from Colorados to Freightliners. He believes it's the idler pulley.

Sent from my SM-N960U using Tapatalk

[2021TrailbossLTMA]

Yea im hoping its something straight forward I mean mine its barely there just when I start to come to a stop or at really low rpms and it jumps from 4 to 8 cylinder mode but im OCD with my vehicles so I dont care how many times it needs to go to GM or if they need to hold onto it until for months until its fixed.  My buddy has a 2020 AT4 6.2 and doesnt have the issue.   Ill post up what they say though. 

 

 

[Transient]

My truck has the dynamic fuel management, so it doesn't just switch from v4 to v8. It has 17 different modes that go from 2 cylinders to all 8. If we're both experiencing the same problem, then it's not AFM or DFM causing the issue. Furthermore, this seems to occur more frequently when idling. The engine is always in V8 mode when just idling.

Sent from my SM-N960U using Tapatalk

[mdes0]

I ran mine without the main belt on and it still made the noise. I also had hoped it was the idler pully. I wasn't able to get the ac belt off at the time though, had just had shoulder surgery. Could be the bearings in the compressor I suppose.

Edited November 26, 2020 by mdes0
Grammer

[Transient]

I ran mine without the main belt on and it still made the noise. I also had hoped it was the idler pully. I wasn't able to get the ac belt off at the time though, had just had shoulder surgery. Could be the bearings in the compressor I suppose.

Hmm....

Ok

Sent from my SM-N960U using Tapatalk

[2021TrailbossLTMA]

So took it to the dealer that I bought the truck from.  They said yea other GM dealer blaming the adaptive exhaust flapper and wanting me to put the factory exhaust back on to check the flapper which was removed is an idiot.

 

They went on a drive and acknowledged that its not normal.  Again happens everytime the truck goes from active displacement to full v8 mode.  Also happens when auto-starting when it shuts off from a stop.

 

They are going to start with cleaning the belts, pulleys, tensioners, etc so im happy that they at least didnt come back and say "yea thats normal" as they had other 6.2L on the lot and they didnt make the same sound.

 

Will post back up once they figure it out but told them I dont want the truck back until its gone.