2015 YUKON NOISE IN CABIN

Wrench589 · December 19, 2015

Getting back to the Yukon, I believe, (just a hunch) that going to very light gauge high strength steel on such a big box of a vehicle and stiff frames and shocks have surprised GM with some of these unexpected problems. They will never be able to totally eliminate all vibration and road disturbances with the current technology. So I fear we are stuck with this until they start going after the body structure.

Just curious how others are being treated on buy backs?.

I couldn't agree more. Using high strength steel is done to get the weight down for the same resultant strength. Unfortunately, that messes with the mass/stiffness ratio, which when dealing with NVH is a big, big deal. Mass absorbs energy. Mass also affects the natural frequency of everything, which ultimately affects resonances. And like you said, it's caught GM off guard.

I've been doing some research into automotive acoustic treatments and dampening. There is a fairly extensive industry out there that serves the OEMs for various products and technologies. Some of these technologies are quite "space age". For example, honeycomb type plastic structures filled with special acoustic foam to provide structural stiffness without the weight. I have to wonder if GM cheaped out and didn't use any of these technologies when making this vehicle lighter, and hence the result. I was always wondering why other brands were making their vehicles lighter and apparently not having these issues, but I can imagine a Mercedes, for example, is full of the latest high tech stuff. GM, having just come out of near bankruptcy, was likely trying the cut as many financial corners as possible and I wouldn't doubt the engineers there wanted to use more technology but were told to forget it. Go cheap and dirty.

A example is have alook at the inside of the rear wheel well. There is one or two little strips of some kind of sound damping foam sprayed on there, but looks pretty skimpy. An another example - the inner wheels wells front and back are not metal any more. It's some kind of felt-like material. Obviously to absorb road noise. But, is that parts of making the whole vehicle flimsy? Who knows. All I know is they messed something up. And they likey know exactly what it is, but it's totally impossible to rectify without major design change. And that just isn't going to happen. At least not on existing vehicles already out there. And from the looks of it, they aren't going to revise the deign for new ones. My guess is they will accelerate the next platform release and relegate this one to type boneyard!!

boazEarl8 · December 19, 2015

FYI I test drove a lot of 16s

All boomed, some worse than others

Maybe half vibrated / buffeted so they can be found

Edited December 19, 2015 by boazEarl8

16Denaliguy · December 19, 2015

Here's what seemed to help our troublesome 2016 Yukon Denali in the last month, so that at least we can drive it out of town. All the issues but the ear/air pressure are still present but softened a bit:

1) Tire pressure @ 30 lbs

2) Front bug deflector

3) 125 lbs of weight put in the rear storage compartment

4) Dynamat in the 4 wheel wells, hood and the entire roof

Just waiting for the new one to come in and we will see how that one drives.

Wrench589 · December 20, 2015

Here's what seemed to help our troublesome 2016 Yukon Denali in the last month, so that at least we can drive it out of town. All the issues but the ear/air pressure are still present but softened a bit:

1) Tire pressure @ 30 lbs

2) Front bug deflector

3) 125 lbs of weight put in the rear storage compartment

4) Dynamat in the 4 wheel wells, hood and the entire roof

Just waiting for the new one to come in and we will see how that one drives.

Any chance you have some photos of the Dynamat you did?

Wrench589 · December 20, 2015

Just had a thought. Has anyone considered lubrication of the u-joints as a possible issue? I'm sure they are not greaseable, so not sure what one would do to inspect or do something about. I've actually never had apart a driveshaft with the new style "sealed for life" u-joints, but wouldn't it be a kicker if the supplier screwed up?

16Denaliguy · December 20, 2015

Any chance you have some photos of the Dynamat you did?

No, but I should have.

Roof - Dyna matted the entire roof including dyna matting over the roof cross ribs.

Wheel wells - removed the 4 fabric wheel liners and dyna matted where ever I could, all exposed metal of the wheel wells themselves. You need to cut and use pieces to try to get all the exposed metal.

**** the real reason I removed the fabric wheel liners was that if I did that I could get to the the inner rear quarter panels which seem so flimsy. But you can't. If you try to get to the 1/4 panels from the inside of the vehicle you would have to remove all the moldings. Inside the rear jack compartment there are other electronic pieces of equipment that I would not dare remove let alone all the interior trim pieces. *****

Hood - dyna matted all the areas under the hood liner that had exposed exterior hood metal. Did not dyna matt the reinforcement areas of the hood.

Wrench589 · December 20, 2015

Thanks for the description, very good. I think I have a pretty good idea what it looks like.

Boy, disappointing with all that Dynamat it didn't completely solve things. Although, if it improved the buffeting, might be a sign it's on the right track.

So, did you remove the headliner yourself, or did you do it when the dealer was doing the TSB?

Zig10 · December 20, 2015

I'm in the middle of my first buy back on a 2015i Yukon XL Denali and have driven 3 2016 XL Denali's and they all vibrate and buffet. The dealer told me that he sees varying amounts of the booming and vibration in different Yukons. I've given up hope of finding one that doesn't do it but don't feel like I have any other options currently. I need a big SUV for a few more years and then I can get rid of it. I used to be a big GM fan and owned all GM vehicles but because of this and the way GM is treating me, I'm in the middle of getting rid of all my GM vehicles (save a few classics). And trying some different brands. I even test drove a Navigator (gasp, Ford was always my mortal enemy:)

Getting back to the Yukon, I believe, (just a hunch) that going to very light gauge high strength steel on such a big box of a vehicle and stiff frames and shocks have surprised GM with some of these unexpected problems. They will never be able to totally eliminate all vibration and road disturbances with the current technology. So I fear we are stuck with this until they start going after the body structure.

Just curious how others are being treated on buy backs?

Are you paying for the miles you put on? If so, now much per mile?

Are you having to pay the increase of MSRP price on the 2016 even though it's the exact same optioned vehicle as the 2015i? The MSRP increased for 2016 by about $2000.

Please give me your feedback.

I guess it depends on your dealer and how old your vehicle was when you brought it to their attention. Mine was 2 days old when I notified them of the problem. Took 6 weeks to go through all the hassle, but mine thus far is heading towards a straight up replacement. No money changing hands or anything.

Keeping my fingers crossed that is stays that way.

Edited December 20, 2015 by Zig10

Elripster · December 20, 2015

I figured out how to tell if a truck will buffet. Simply watch the roof while you shut a door. If the roof jumps you will have problems.

This might also be a good way to show your dealer the issue.

Frank

Sent from my SM-N910V using Tapatalk

16Denaliguy · December 20, 2015

Thanks for the description, very good. I think I have a pretty good idea what it looks like.

Boy, disappointing with all that Dynamat it didn't completely solve things. Although, if it improved the buffeting, might be a sign it's on the right track.

So, did you remove the headliner yourself, or did you do it when the dealer was doing the TSB?

TSB was done by the dealer and they even performed the TSB to the extreme, adding extra glue extra shims just knowing how anal I am with my vehicles.

I've dyna-matted all my vehicles anyway, well at least the last 8 (4 Avalanches - Denali - 3 Escalades) and it really makes a difference in the interior noise levels. And now this 2016 Denali.

A couple weeks after the dealer performed the headliner TSB and fixed the leaking sunroof, I along with a auto body friend removed the headliner and dyna matted with 2 and in some areas 3 layers of dyna matt (not cheap). I took care of the hood and the wheel wheels myself.

I've got my own money and alot of time trying to help out GM, the dealership, and my fellow forum friends in trying to help determine or help alleviate these problem vehicles. There is just something about these vehicles that cannot be figured out. Even the GM field engineer has tried everything and they gave up. Said we got what we got and it won't be fixed until 2018. Not sure where he got the 2018 figure from but that's what we were told.

The same engineer unbeknownst to me told the selling dealer that is 4 hours away (that he also services) that he had worked on a 2016 Yukon Denali 4 hours away that he can't fix. So when I showed up at the selling dealership later on in the month while on vacation the service manager told me he spoke to the GM field engineer and was told the same statements that the field engineer explained to me a month earlier about my Denali. These conversations that occurred are nose to nose not phone calls, not emails or texts. Person to person.

Edited December 20, 2015 by 16Denaliguy

The Zip · December 21, 2015

I figured out how to tell if a truck will buffet. Simply watch the roof while you shut a door. If the roof jumps you will have problems.

Don’t know how accurate this is in determining if the truck will buffet or not, but after driving my truck for about 2 years and over 15K miles with no issues, I went out and watched the roof while closing the door; no movement in the headliner.

Elripster · December 21, 2015

My roof jumps big time.

Frank

Sent from my SM-N910V using Tapatalk

Zig10 · December 21, 2015

TSB was done by the dealer and they even performed the TSB to the extreme, adding extra glue extra shims just knowing how anal I am with my vehicles.

I've dyna-matted all my vehicles anyway, well at least the last 8 (4 Avalanches - Denali - 3 Escalades) and it really makes a difference in the interior noise levels. And now this 2016 Denali.

A couple weeks after the dealer performed the headliner TSB and fixed the leaking sunroof, I along with a auto body friend removed the headliner and dyna matted with 2 and in some areas 3 layers of dyna matt (not cheap). I took care of the hood and the wheel wheels myself.

I've got my own money and alot of time trying to help out GM, the dealership, and my fellow forum friends in trying to help determine or help alleviate these problem vehicles. There is just something about these vehicles that cannot be figured out. Even the GM field engineer has tried everything and they gave up. Said we got what we got and it won't be fixed until 2018. Not sure where he got the 2018 figure from but that's what we were told.

The same engineer unbeknownst to me told the selling dealer that is 4 hours away (that he also services) that he had worked on a 2016 Yukon Denali 4 hours away that he can't fix. So when I showed up at the selling dealership later on in the month while on vacation the service manager told me he spoke to the GM field engineer and was told the same statements that the field engineer explained to me a month earlier about my Denali. These conversations that occurred are nose to nose not phone calls, not emails or texts. Person to person.

If I walked into one of my clients offices after engineering a system that didn't work and left them with the line that "they got what they got" I am not sure I would make it out of the building with my ass still attached to my body. And I am pretty sure I would be unemployed shortly after.

In fact, I would now LOVE to do one of GMs new assembly lines for them. Maybe in the installation when the car is halfway down the assembly line the jig that hold it in the air releases and drops the car on to the ground...upside down. When one of the commissioning engineers complains, I would simply shrug my shoulders and refer them to the current generation large SUV platform for reference.

Edited December 21, 2015 by Zig10

FogDucker · December 21, 2015

My roof jumps big time.

Frank

The roof pops up in the 2015i Suburban I'm in when I close one door. It buffets at 60kph and worse at 120kph.

My friends 2014 Tahoe has the same roof movement when closing the door, but does not buffet at any speed.

I just compared them side by side in the driveway.

Sent from my SM-G925W8 using Tapatalk

Wrench589 · December 21, 2015

Stumbled across this about older GM pickups.

http://www.justanswer.com/chevy/29lyw-silverado-that-issuing-vibration-cab-mount-supresses.html

"Frame beaming".... I'm thinking that is the term GM used to describe the frame actually bending in one of its natural mode shapes. Now, be aware that everything flexes to a certain degree. The question is, will it result in a "problem". What I find incredibly interesting is that frame beaming has happened in the past and thus, can be added to the list of possible root causes here. And if it is the frame, then we are all screwed. Cause I'm sure there is NO practical fix.

Makes one wonder how this could have every got through design and testing. Well, don't forget. A lot of vehicles get designed and tested on the computer these days. Those images you see on the TV ads of a vehicle up on some kind of road simulator or shaker are just that - images. In order to cut costs and reduce cycle time, all manufacturers take shortcuts. And computer simulations cut time. But, they don't always give the whole answer. All I'm saying is it's totally possible such a fundamental screwup could get through and end up in the production vehicles. And as that post says, any vibrations make it worse, so GM will be chasing all those vibrations. Hence, all the Roadforce Balancing and the like. And, all to no avail.

This goes back to a post I made many months ago, sharing a Technical Paper in found on this exact topic and the research the author had done. Looking more and more like a possibility, even if it is pure speculation at this point.