Metallic Rattle While Accelerating - Dealer Can't Reproduce (video)

[AshleyM]

While accelerating around 2-2.5k RPMs, a noticeable metallic chain-like rattle comes from the engine area in my 2023 GMC Yukon Denali Ultimate (34k miles).

My vehicle is under warranty, and I've demonstrated the problem for the shop foreman, but he "can't hear it." Another tech said he did hear it and that it "wasn't a normal noise," but the following day, he said he was mistaken.

I made the following video for them, but the service advisor admitted that they didn't watch it and their official position is that they "can't reproduce it". She said the shop foreman checked "everything" in the engine bay.

Dealer is Thompson GMC in Raleigh, NC.

Does anyone know what could be causing this sound (timestamps 0:02, 0:06, 0:10, 0:13, 0:17)?
https://youtube.com/shorts/IchzTs6mVrQ

 

[blanchard7684]

First thing I would check is for loose material or loose trim inside the cabin somewhere.

To me it sounds like something is loose and getting excited by the specific frequency of the engine accelerating at 2k-2.5k rpm.

I had a loose trim piece on bottom leg of third row seat. The plastic cover over the bolts was loose and the frequency of the suspension had to be just right to get it to excite and rattle. I took the piece off and bent the small metal tabs a bit and that fixed it.

If not interior noise, then check for loose heat shields on exhaust, loose skid plate, or road debris that got trapped in a spot that would vibrate. It does resemble a socket vibrating on a metal surface.

If that doesn't check out then it could be engine related.

 

[AshleyM]

I appreciate the response & advice.

Noise is coming from the engine bay, and the service advisor told me that the shop foreman checked "everything". I asked if that meant heat shield, pulleys, lifters, timing chain tensioner, engine mounts, etc., and she said "yes".

They had my Yukon for 10 days and given my experience, I don't believe they checked anything other than the heat shield & pulleys.

When I demoed the issue for the shop foreman multiple times and he said he "couldn't hear it" but his hearing "wasn't the best anymore", I knew he wasn't going to look into it any further.

The service advisor also told me that no matter how much evidence I provide, they will not investigate further.

 

[WalleyeMikeIII]

My ears must be bad, I don't hear it in your video

That siad, if the dealer says "can't reproduce" My suggestion is 2 things...
1) show them the video..
2) Request the service manager go for a ride with you and confirms he hears it...

But based on your most recent post...try a different dealer!

 

[AshleyM]

Noise (metallic rattle) is easier to hear with headphones on.

I have demoed noise separately for the shop foreman, who I believe is also the service manager, and another tech. The tech said he heard it and would open an attack/action case with GMC, but the next day, according to the service advisor, he said he didn't hear it.

I have confirmed via YouTube stats on the private video I shared with them that no one watched it.

 

[adventurenali92]

Noise (metallic rattle) can be heard at timestamps 0:02, 0:06, 0:10, 0:13, 0:17 and is easier to hear with headphones on.

I have demoed noise separately for the shop foreman, who I believe is also the service manager, and another tech. The tech said he heard it and would open an attack/action case with GMC, but the next day, according to the service advisor, he said he didn't hear it.

I have confirmed via YouTube stats on the private video I shared with them that no one watched it.

As walleyemike said it’s time to take to another dealer and have it checked out by a different shop manager or tech. Sounds like the current shop manager isn’t skilled in diagnostics beyond what his service manual suggests, or he’s not motivated to go beyond the service manual for whatever reason. If you’re not willing to go to another dealer escalate the case passed the service manager to GM, and see if they will push the service manager to go any further.

 

[WalleyeMikeIII]

As walleyemike said it’s time to take to another dealer and have it checked out by a different shop manager or tech. Sounds like the current shop manager isn’t skilled in diagnostics beyond what his service manual suggests, or he’s not motivated to go beyond the service manual for whatever reason. If you’re not willing to go to another dealer escalate the case passed the service manager to GM, and see if they will push the service manager to go any further.

By GM here, you mean the dealer general manager, right, not General Motors (although that could be an avenue too!)

 

[2024 White Tahoe]

While accelerating around 2-2.5k RPMs, a noticeable metallic chain-like rattle comes from the engine area in my 2023 GMC Yukon Denali Ultimate (34k miles).

My vehicle is under warranty, and I've demonstrated the problem for the shop foreman, but he "can't hear it." Another tech said he did hear it and that it "wasn't a normal noise," but the following day, he said he was mistaken.

I made the following video for them, but the service advisor admitted that they didn't watch it and their official position is that they "can't reproduce it". She said the shop foreman checked "everything" in the engine bay.

Dealer is Thompson GMC in Raleigh, NC.

Does anyone know what could be causing this sound (timestamps 0:02, 0:06, 0:10, 0:13, 0:17)?
https://youtube.com/shorts/IchzTs6mVrQ

I could not hear the noise.

Is it possible the noise you are hearing is engine pre-detonation (also called engine knocking)? Are you familiar with engine knock and its sound?

Are you using premium fuel in your vehicle? You didn’t mention the engine size, but doesn’t your model come standard with the 6.2 L engine?

Modern engines have knock sensors, which “hear” any detonation and automatically cause the engine management system to retard the engine timing.

If there is an issue with the sensor system, it could enable the engine to knock (especially with lower-octane fuel).

 

[AshleyM]

I'm familiar with engine knock and if it were that the dealer would have been able to diagnose it quickly.

The noise is easiest to hear in my video at 0:02 seconds. It sounds like a "shudder" but only occurs when accelerating around 2k RPMs. It is most apparent with headphones and the volume turned up.

 

[tahoe81]

I hope you get it sorted out, but I know all too well about dealers and "not hearing" noises. My 2022 Tahoe has been nothing but one different rattle or noise after the other and initially every time I take it in they never hear it until I press to ride with a foreman and force them to hear it. I actually just got me vehicle back yesterday for an issue which the foreman heard and they allegedly heard it yesterday and then replaced a plastic clip somewhere that was broken which they claim fixed the issue. Low and behold the noise remains the second I drove it off the lot. I went straight back and had to deal with an advisor getting snippy with me because "evidently the noise is something only I can hear"

The funny thing? Using the Chevrolet App on my iPhone, I can see the location of my vehicle and I can even set alerts when my vehicle arrives or leaves an address. I never got any notification the entire time they had my vehicle which means they didn't even drive it (which I've suspected in the past of them when they tell me they can't hear something that's clear as day)