2015 YUKON NOISE IN CABIN

Zig10 · November 25, 2015

Dear CI, I feel that the glass should be close and tight to the window frame. Seal tape would still put the glass away from the frame a bit as you are moving the glass away from "home base" My glass is very tight and close to the "frame". Took my wife to the grocery store today. Drove up to 85 mph on the back roads and still no problem. The only "Boom " I heard was the XM station that plays R & B. I love the Stereo in this car. So far , I love this car. It drives like........ A Limo. I also have my fingers crossed. Good luck to you and hope you can resolve your issue. With best regards, Booty

So is there an adjustment that can be made to pull it in? The tolerances can't all be THAT bad that there is a 3/8" - 1/2" difference in tightness on the glass from one vehicle to another.

Edited November 25, 2015 by Zig10

Elripster · November 25, 2015

Yes, that was done back in the spring. C/w Dynamat. No improvement.

Have you checked to see if the bows are attached?

Frank

Sharky146 · November 26, 2015

Ok. I'll do that. It sounds like there is at least one other user that has had success with your procedure. I'll let you know how it goes. Thanks for the info and advice.

UPDATE: I've been experiencing similar buffeting noises in my 2016 Tahoe LT. After reading this forum, I was fairly sure that it was the "oil-canning" of the roof that was causing this issue. Well, yesterday I brought it the dealership where I purchased the vehicle, and took the shop foreman for a ride. To his credit, he did not try to diagnose my problem before experiencing the noise for himself. However, during the ride he convinced me that the roof that is not causing this noise. He admitted that the early 2015s had a problem with the roof bows not being properly secured to the roof skin. However, that specific problem was fixed in later 2015s and the 2016s.

The shop foreman convinced me that the my problem relates to the vehicle's exhaust system. He stated that the full size SUVs and the Silverado have a problem with the exhaust that causes a pulsating droning sound in the cabin. The root of the problem has to do with how exhaust air flows through the system. Apparently there is an issue with the baffles in the muffler. The sound is particularly noticeable when the vehicle switches from V8 to V4 mode, which can be observed by selecting the appropriate display on the instrument panel. While the sound is most noticeable while in V4 mode, it can be heard in V8 mode as well. He said that GM is aware of the problem, and is working on a solution. He mentioned that GM has solved the problem for the Silverado truck line, but is still working on the SUV problem. The foreman had recently spoken to the GM field technician, who said that he expected a solution from GM by January 2016.

While there is no immediate fix for my problem, I'm happy that there is a solution in the works. Now we just have to see if GM follows through!

I hope this helps those with later 2015s and 2016s. I'll report back in January with an update.

-Joe

(By the way, while I initially thought that my roof was the problem, I had a sneaking suspicion that it wasn't. Let me tell you why... If the fluctuating cabin pressure sensation was being caused by the roof pulsating up and down, it should stop once you equalize the pressure by opening a window. However, in my car the sound is present regardless of window position.)

Booty · November 26, 2015

So is there an adjustment that can be made to pull it in? The tolerances can't all be THAT bad that there is a 3/8" - 1/2" difference in tightness on the glass from one vehicle to another.

Zig, Adjustment ? I do not know. If the hinges and the latch are welded then ....NO. If they are bolted....Maybe there is some room for adjustment. "The Devil is in the details" meaning that if the assembly guy welded or bolted the hinges and latch out of spec then you have a sloppy fitting glass. And it could be that engineering has made the mistake and the assembly guy is doing his job right. All I know is my glass is tight and the glass on the first vehicle was not tight. I stumbled on to this forum looking for accessories and had no idea of the huge problem that exists. I am a witness that it does. Happy Thanksgiving to you and everyone, All the best, Booty

Zig10 · November 26, 2015

UPDATE: I've been experiencing similar buffeting noises in my 2016 Tahoe LT. After reading this forum, I was fairly sure that it was the "oil-canning" of the roof that was causing this issue. Well, yesterday I brought it the dealership where I purchased the vehicle, and took the shop foreman for a ride. To his credit, he did not try to diagnose my problem before experiencing the noise for himself. However, during the ride he convinced me that the roof that is not causing this noise. He admitted that the early 2015s had a problem with the roof bows not being properly secured to the roof skin. However, that specific problem was fixed in later 2015s and the 2016s.

The shop foreman convinced me that the my problem relates to the vehicle's exhaust system. He stated that the full size SUVs and the Silverado have a problem with the exhaust that causes a pulsating droning sound in the cabin. The root of the problem has to do with how exhaust air flows through the system. Apparently there is an issue with the baffles in the muffler. The sound is particularly noticeable when the vehicle switches from V8 to V4 mode, which can be observed by selecting the appropriate display on the instrument panel. While the sound is most noticeable while in V4 mode, it can be heard in V8 mode as well. He said that GM is aware of the problem, and is working on a solution. He mentioned that GM has solved the problem for the Silverado truck line, but is still working on the SUV problem. The foreman had recently spoken to the GM field technician, who said that he expected a solution from GM by January 2016.

While there is no immediate fix for my problem, I'm happy that there is a solution in the works. Now we just have to see if GM follows through!

I hope this helps those with later 2015s and 2016s. I'll report back in January with an update.

-Joe

(By the way, while I initially thought that my roof was the problem, I had a sneaking suspicion that it wasn't. Let me tell you why... If the fluctuating cabin pressure sensation was being caused by the roof pulsating up and down, it should stop once you equalize the pressure by opening a window. However, in my car the sound is present regardless of window position.)

Just thinking out loud, wouldn't that mean that the drone is present any time the vehicle is in that same RPM range? And why would it only occur between 40-45 MPH on a vehicle (at least on mine)? I have to admit that I did not try shifting to a lower gear at those speeds, but if it is an exhaust back-pressure issue then running the engine at a different speed should solve the problem, at least temporarily.

I'll have to give that a try.

Edited November 26, 2015 by Zig10

Wrench589 · November 26, 2015

Just thinking out loud, wouldn't that mean that the drone is present any time the vehicle is in that same RPM range? And why would it only occur between 40-45 MPH on a vehicle (at least on mine)? I have to admit that I did not try shifting to a lower gear at those speeds, but if it is an exhaust back-pressure issue then running the engine at a different speed should solve the problem, at least temporarily.

I'll have to give that a try.

Early on in this whole thing I played around with engine rpm by putting the transmission in manual and forcing a downshift. I saw no change to the buffeting/drone. So, I am not sure I agree it is an exhaust issue. In fact, I have a hard time seeing how the exhaust system, which is outside the cabin, could result in a pressure sensation inside the cabin. The only way to create pressure inside the cabin is to physically disturb the air inside the cabin. Now, it is possible the exhaust is exciting the cabin walls or something inside the cabin, and hence the conclusion the problem is the exhaust. But the reality in dealing with any sound or vibration issue, there are always two components to the noise....the input, and the output. Take a guitar, for example. Sitting in the table, it makes no noise. Strum a string with your finger, and it makes noise. Is the finger the cause of the noise? Or the string? Or the massive box resonating below the string? Well, the answer is all three make up a "system" which ultimately results in the sound.

GM is stuck on trying to eliminate the finger. Road force balancing tires. Ring and pinions. Now exhaust systems. The problem that approach, IMHO, is that in a motor vehicle, there will always be fingers - potholes, rough road, tires wearing, and on and on. They are wasting their time and ours. They need to focus on the big box below the string. Or possible the string. Until they do, these SUVs will continue to be the big turd that they are.

FogDucker · November 26, 2015

Early on in this whole thing I played around with engine rpm by putting the transmission in manual and forcing a downshift. I saw no change to the buffeting/drone. So, I am not sure I agree it is an exhaust issue. In fact, I have a hard time seeing how the exhaust system, which is outside the cabin, could result in a pressure sensation inside the cabin. The only way to create pressure inside the cabin is to physically disturb the air inside the cabin. Now, it is possible the exhaust is exciting the cabin walls or something inside the cabin, and hence the conclusion the problem is the exhaust. But the reality in dealing with any sound or vibration issue, there are always two components to the noise....the input, and the output. Take a guitar, for example. Sitting in the table, it makes no noise. Strum a string with your finger, and it makes noise. Is the finger the cause of the noise? Or the string? Or the massive box resonating below the string? Well, the answer is all three make up a "system" which ultimately results in the sound.

GM is stuck on trying to eliminate the finger. Road force balancing tires. Ring and pinions. Now exhaust systems. The problem that approach, IMHO, is that in a motor vehicle, there will always be fingers - potholes, rough road, tires wearing, and on and on. They are wasting their time and ours. They need to focus on the big box below the string. Or possible the string. Until they do, these SUVs will continue to be the big turd that they are.

Agreed, except for the turd part. ;) I don't think it's exhaust related, at least for me. I too tried various rpms using manual mode and while driving in the sweet spot - zero change.

I also agree that these new "boxes" are more sensitive to nvh. I think the buffeting is caused by vibration. The pickup truck folk feel it. We SUV (box) folk feel it and hear it. Maybe the dynamat fixed the symptom (booming) but not the root cause (vibration).

My update: my dealership had my Yukon for 3 days a couple of weeks ago; field engineer spent some time with it and pico-metered it. 2 tires are being replaced today and an entirely complete axle (rotor to rotor; not just ring & pinion) is on order.

I haven't put my snow shoes on just yet as I want to see if it makes any difference. The fellow whom I bought my Sierra AT wheels from did suggest that there was varied quality from the Chinese made wheels that we all get and that they're not all sourced from the same supplier.

Lots of variables with possibly more than one problem. Only on a percentage of vehicles. That's tricky!

16Denaliguy · November 26, 2015

Well here's an update:

Hood was dyna-matted.

Wheel wells dyna-matted.

Headliner was removed for the second time and the entire roof was dyna-matted with 2 layers.

All TSB's have been performed including all the roof bows were shimmed and glued.

RESULTS:

Cabin is quieter but booming is still there at slow speeds over bumps in road or parking lots.

Buffeting is still present, reduced, but still very noticeable.

Air pressure issues are pretty much gone.

Tires are under 10 lbs for 3 the 4rth is at 12 lbs.

When towing a 28 foot trailer 4 hours no buffeting or booming at all!!

boazEarl8 · November 26, 2015

Well here's an update:

Hood was dyna-matted.

Wheel wells dyna-matted.

Headliner was removed for the second time and the entire roof was dyna-matted with 2 layers.

All TSB's have been performed including all the roof bows were shimmed and glued.

RESULTS:

Cabin is quieter but booming is still there at slow speeds over bumps in road or parking lots.

Buffeting is still present, reduced, but still very noticeable.

Air pressure issues are pretty much gone.

Tires are under 10 lbs for 3 the 4rth is at 12 lbs.

When towing a 28 foot trailer 4 hours no buffeting or booming at all!!

Great update. Dealer did it? Any charges?

What's your distinction between booming and buffeting? I assumed people used buffeting to refer to repeated booms vs just once or twice ie on a bumpy road, the series of booms = buffeting?

Wrench589 · November 27, 2015

When towing a 28 foot trailer 4 hours no buffeting or booming at all!!

Now, that is very interesting. Any chance you ever pulled the same trailer before all the Dynamat?

Cl Houn · November 27, 2015

Ok. Would we be able too say the dynamat reduced buffeting and eliminated ear pressure to a satisfactory level.

Also when you say all tsb was done do you mean the rear end and drive shaft too or just the roof bows?

16Denaliguy · November 27, 2015

Drive shaft and rear end gears were checked and all within GM specs.

2 of my smaller trailers with a lighter tongue weight would cause a rythmic harmonic vibration between 47 to 63 mph. This larger trailer I did not get out of storage until our vacation so I cannot give a before and after dynamat.

We dynamatted the Denali ourselves.

The booming noise is at low speeds when hitting a bump or expansion joint sounds similar to a low end thump from a subwoofer. buffeting is at higher speeds and sounds like the rear windows are down or a helicoptor overhead.

FogDucker · November 27, 2015

Has anybody tried removing the spare tire?

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FogDucker · November 28, 2015

Has anybody tried removing the spare tire?

I tried it today - no change. Thought it was worth a try.

If anything, getting the spare off was a good exercise to try the first time in the driveway and not at the side of a highway in a foot of snow!

Cl Houn · November 28, 2015

Drive shaft and rear end gears were checked and all within GM specs.

2 of my smaller trailers with a lighter tongue weight would cause a rythmic harmonic vibration between 47 to 63 mph. This larger trailer I did not get out of storage until our vacation so I cannot give a before and after dynamat.

We dynamatted the Denali ourselves.

The booming noise is at low speeds when hitting a bump or expansion joint sounds similar to a low end thump from a subwoofer. buffeting is at higher speeds and sounds like the rear windows are down or a helicoptor overhead.

Do you fell its acceptable now