2015 YUKON NOISE IN CABIN

AceofSpades · May 15, 2015

OMG, I was about to buy a 2015 Yukon LT w/ 10k miles on it until I came across this thread! Drove it today, loved it. My stomach dropped reading this thread and thinking I could be in your situation of a defective truck with no manufacturer support. This is absolutely pathetic by GM to continue to sell a defective vehicle, and not take care of existing owners. I would be livid if my kids had headaches and GM did nothing about it.

I feel for you all. I hope somebody at GM gets some sense to take care of this. Thank you for posting this to prevent this from happening to me. We've driven BMW and Mercedes for the past 12 years (our last Grand Cherokee was junk). Thought maybe it was time to try American, guess not. I'm bummed since this looked to be such a great truck for the money.

Back to the MB and Infiniti dealer to take another look at their SUV's.

Come on GM, you people are better than this. Geez.

BillyJack · May 16, 2015

Well, I'm at an absolute loss. My 2015 Tahoe LT (6spd Auto, 5.3L) not only has the cabin noise issue that is making eveyone sick and irritated in my family but I also have the low idle to the point of shaking the Tahoe and hard shifting at low speeds issues. Took me forever to finally pull the trigger on a vehicle at this price point and I can't believe what I'm going to have to go through now. With the noise, it's undriveable for my family. It's going into the shop for the 2nd time on Monday. The first time I took it in, I hadn't researched the issue and almost thought I would get laughed off the lot because they might think I'm nuts. Now I at least know my sanity is intact.

I got this because I rent 2 - 3 Tahoes a month and all have been great. They are all responsive through the gears and dont' have any vibration or cabin noise. Then, I get home and get in mine and can't belive how bad it is. This will simply be trip #2 but at least I'm educated on the issue now. I will most certainly be looking for a buy back if this isn't resolved as I can't even get my family to ride in my family vehicle.

Wrench589 · May 17, 2015

I got this because I rent 2 - 3 Tahoes a month and all have been great. They are all responsive through the gears and dont' have any vibration or cabin noise. Then, I get home and get in mine and can't belive how bad it is. This will simply be trip #2 but at least I'm educated on the issue now. I will most certainly be looking for a buy back if this isn't resolved as I can't even get my family to ride in my family vehicle.

Interesting that your rentals have been noise free. The three rentals I've had all had the noise. All three had slightly different magnitude, but basically they all did it. Your experience is noteworthy.

Gmjunky · May 19, 2015

Going in today for the noise in cabin issue, and loose driver seat, and vibration at speed, and disintegrated rear passenger headrest, and who knows what else.

AceofSpades · May 20, 2015

I upgraded to an Escalade rental this week during a business trip to test out the truck, and see if it had the issues described in this thread. Brand new truck, 100 miles on it had to have Avis come and pick it up from me. Not Drivable on the highway, front end shimmy and very loud inside. They swapped out for another Escalade w/ 15k miles on it and much better but can still sense the issues are there.

I feel for you all. I hope GM figures out how to fix this, I still want to buy a Tahoe but cannot until its completely fixed.

DLB · May 20, 2015

I've been following this thread, and other related threads, since the beginning. After owning our Yukon for a year, we have realized that we're not going to get used to the noise. I had my dealer fix all the recalls last week as well as the shifting seat (they replaced the entire seat frame). They asked me to bring it back tomorrow so I can take a tech for a ride and point out the issue. I've spoke with GM customer service a few times recently and they encouraged me to continue taking it in until they can figure out how to fix it. One of the CS guys I spoke with said it's going to take a lot of phone calls, from a lot of people, before GM will really focus on this issue. He didn't come out and say it, but I got the impression he was aware of this problem. So everyone needs to call GM customer service as much as possible.

On a side note: I notice this noise is amplified at least twice as much while towing my trailer. Does anyone else notice this?

TOBTEK · May 20, 2015

HERE'S something to look at. Don't know about you all, But I'm OVER this whole GM Debacle.

http://www.mbusa.com/mercedes/future/model/model-All_New_2016_GLE_SUV

LOOKING for options that will pull the boat, fit 7 people, And Won't create head aches, and spend 50% of the time at the dealers service dept.

Mr. GM......... This whole thing is a complete JOKE ! $85,000.00 vehicle that rides like a Tank, Makes booming noises over every little bump, everything breaks.... just a joke!

Wrench589 · May 21, 2015

HERE'S something to look at. Don't know about you all, But I'm OVER this whole GM Debacle.

http://www.mbusa.com/mercedes/future/model/model-All_New_2016_GLE_SUV

LOOKING for options that will pull the boat, fit 7 people, And Won't create head aches, and spend 50% of the time at the dealers service dept.

Mr. GM......... This whole thing is a complete JOKE ! $85,000.00 vehicle that rides like a Tank, Makes booming noises over every little bump, everything breaks.... just a joke!

Well, that "new" GLE looks identical to this years M-class suv, so I don;t know whats so new about it. That said, their GL-class is essentially the M-class stretched out a biut - and not anywhere close to the size of a Suburban or Yukon XL. I know - I looked at one very closely. With my tape measure - although I didnt need a tape measure to see that the amount of room behind the 3rd row with in GL is pretty much useless compared to the Yukon XL. Not even close.

NO, unfortunatley there are only 2 vehicles made that are in the class of a true "big" SUV - Suburban/Yukon XL and FOrd Expediation Max. These are full stretched out SUV's. Easy to spot - the second row door is full size, not chopped out to fit over the rear wheelwell. Every import barnd "full size" suv is chopped out. They may look big, but in reality they aren't. At least not where it counts. My take is that all those vehicles (except the big Lexuas, I think) are uni-body construction instead of body-on-frame. And the manufacturers may not be able to stretch the unibody out any further without compromising something.

As for towing with that new GLE...well, looks good in the photos. Old school thinking says never tow heavy loads with a unibody vehicle. Alsways want a full frame vehicle for towing. I have always subscribed to that line of thinking. But, with modern design and manufacturing technologies, I guess it is possible to build a vehicle that can withstand the abuse of towing without impacting the structural integrity of the tow vehicle. I guess. Maybe. But wait - isn;t it all that "new technology" thinking that got these new GM into the trouble we're in now??? Hmmmmmmmmmmm.

If Ford ever updates the Expedition Max so it's not 12yrs old and outdated, I might just trade the Yukon in and get out of the mess!

FogDucker · May 21, 2015

Hi all,

I took delivery of my 2015 Yukon Denali [6.2L; 8A; SWB; 20" Continentals] last week. It was built the week of 20. April and it has 'the boom'. It has exhibited no other noises or vibrations.

I've only driven about 1,000km [600 miles] including two 2+ hour drives, but have heard the buffetting/boom sound described in this thread. I've heard it in/around speeds of 100kph [60mph] and sometimes when driving slowly over moderate bumps. It sounds like it's originating from the rear of the vehicle via the rear suspension. Not always and in my opinion, not that bad. It's possible that I have a mild case or that it worsens over time. My wife and 3 kids didn't notice anything on those two 2+ drives even when the stereo was off.

I can best describe 'the boom' as a broken subwoofer being fed audio from a heavy metal drummer playing double bass pedals.

I'll post back should anything change, but as of this moment, I'm very happy with my purchase. I'm loving the 6.2L / 8 speed combo and the exhaust note is music to my ears at any RPM. Fit and finish is very good [for GM standards]. The Yukon is comparable in quietness to the Buick Enclave that it replaces, which was very quiet.

I look forward to putting some miles on it and will be pulling a trailer over the next few weeks.

--
Marc

DLB · May 21, 2015

Took mine into the dealer this morning and drove around with a tech.

His words: The low speed booming over bumps is due to the fact that the sound of the rear suspension has to go somewhere and it resonates in the cab. I've only owned pickups before this Yukon, so I couldn't argue with that. He then said the buffeting sound is simply due to the aerodynamics of the vehicle. Wind bounces off the roof and side panels of the vehicle causing the booming sound. He said that it may get worse depending on weathers conditions, temperature, etc.

I explained that it gets considerable worse while towing my car hauler at speeds around 40-45 mph, but he didn't really have an explanation for that.

Anon2015 · May 21, 2015

That's because he is largely talking BS. The tech is repeating, or attempting to repeat, what someone else told him without having any understanding or background as to the cause, solution, or of acoustic/vibrational dynamics.

"The low speed booming over bumps is due to the fact that the sound of the rear suspension has to go somewhere and it resonates in the cab." Ok; but, in a properly engineered vehicle it (a) wouldn't go inside the cabin environment; and, (b) the resonance frequency of the cab would have been damped. That being said, if that statement were 100% accurate, why is it not an issue with all other vehicles? (let's keep it simple...in last year's Tahoe/Yukon line). BTW, the resonance inside the cabin would change based upon interior volume and number of salt water sound absorption bags -- humans and dogs.

Buffeting due to aerodynamics of the vehicle. Ok. In a properly engineered vehicle, bracing would have been installed to prevent vibration at the buffeting frequency(ies). Furthermore, multiple changes to the roof and roof damping materials resulting in no change to the buffeting. It should be noted that should that statement be 100% accurate, the buffeting frequency would change between LWB and SWB vehicles and, based upon what I have seen, that is not the case. That falls under the category of "if you want to B***S***t me, come up with something better."

BUT ON THE BRIGHT SIDE...he just admitted GM has a design flaw. He has admitted to a design flaw which would have been easily discovered during testing (prior to production and product release), and therefore admitted to negligence on the part of GM. On the other hand, he is not an engineer, nor an employee of GM...so he didn't admit to anything, he simply accused GM (I certain GM will be happy about that); but, if he is repeating an official position of GM as was told to him by a GM employee, maybe we can all get free replacement vehicles.

Edited May 21, 2015 by Anon2015

Wrench589 · May 21, 2015

Good post, Anon.

"The low speed booming over bumps is due to the fact that the sound of the rear suspension has to go somewhere and it resonates in the cab." Ok; but, in a properly engineered vehicle it (a) wouldn't go inside the cabin environment; and, (b) the resonance frequency of the cab would have been damped. That being said, if that statement were 100% accurate, why is it not an issue with all other vehicles? (let's keep it simple...in last year's Tahoe/Yukon line). BTW, the resonance inside the cabin would change based upon interior volume and number of salt water sound absorption bags -- humans and dogs."

What's interesting about this is the huge number of technical papers published on the topic of vehicle "boom" or "drone". I counted several hundred papers in SAE alone on the topic based on one search alone. THe bottom line - it is a very common issue with vehicles that has been studies and analyzed to death, by all the auto makers. These papers are all published by various engineers working for one of the companies, be it Ford, GM, Toyota, Hyundai, etc, etc. That tells me that the phenomenon is common. How the manufacturers deal with it is another thing. I highlt suspect that what GM tried to do on this new SUV platform is take the easy way out. Instead of applying more "traditional" methods to design, test, analyze, modify, and correct the boom, they decided to use their "state of the art noise cancellation technology" to do all the dirty work. Problem is, it doesn't work. Why do I suspect that? Because in a GM press release on the Terrain when they introduced it, they said they were using noise cancellation technology to take car or boom sounds generated by lugging the engine for fuel economy. They were boosting about it. Makes me suspicious, to say the least.

Now, do other vehicles have booming? Turns out, I would say absolutely. Since delving into this on our Yukon, I listen carefully to every vehicle I drive now. Turns out, my own daily driver, a 2009 Ford Explorer, totally booms. but here's the thing - I never noticed it before. Why? It's not that severe. It only does it over noticeable bumps, and it seems to dampen out almost immediately. And, it not as loud when it does do it. Whereas the Yukon seems to do it over just about any road disturbance, seems to sustain much longer (like a bouncing vehicle with no shocks), and is louder when it does do it (which is most of the time). So, it tah because it's a bigger vehicle? Well, it's been years since I've been in a previous generation Suburban, so i can't say from personal experience. But, seems like other have said the previous generations Suburbans "don't" do it. Which I take to mean it's not very noticable, like my Explorer was/is.

As for the acouistic resonances in the cab, I've actually done the calcualtions for the various modes (and there are many of them), and none seem to coincide with the frequencies I have measured acoustically inside the vehicle. The measured are lower then even the lowest calulated mode. So, I suspect that this is not an acoustic resonance, but instead a mechanically/structuraly induced acoustic response. And I have not done any structural modelling to predice those modes - and I likely never will as that is extremely complicated. NOw, I will admit that my calculations for the acoustic mode does not take into account any of the modifiers inside the cab - the seats, the carpet, the console, the salt bags (as Anon call us). But, I believe that those tend to increase the mode frequencies, not lower them, so wouldn't make them align with the measured sound anyway. Still, worth pointing out.

So, the comment that the rear suspension is transmitting up into the cab is actually one the prime situations that causes mechanically induced boom in a cab, turn out. So much so that even problems with ring gear runout, backlash, or u-joints can transmit up through the rear suspension and cause boom. But to Anon's point, a properly engineering vehicle will control these to the point where the occupants do not notice them.

As for the higher speed "buffeting", I am waffling on whether it is the same thing as the boom/drone, or a separate exciting force and response. I'm not sure. I do know that when the dealer loosen the body mounts, drove the vehicle to neutralize them, the torqued them back down, that the buffeting at 100 kph seemd to be gone - for about 2 weeks. Now, I am starting to hear it again. So, the body mounts definitetly play a role, and that could be th transmission path for whatever is causing the buffeting. Which of course has nothing to do with aerodynamics! But, note that even the body mount adjustment did nothing to improve the boom/drone at all speeds - that remained the same.

And then there is the observation I have about how opening and closing the rear doors can also cause the boom. The simp;ly detent in the door mechanism generates a boom that can be heard if you sit in the seat and open/close the door repeatedly. Even my daughter and wife can clearly hear it. (Need to be sitting in the seat - won't hear it standing beside the vehicle). Now, those doors are structurally coupled to the body, so are obviously exciting the same thing that other disturbances are exciting. The question is - what? I still maintain that the only surface big enough to generate enough air movement that a person will feel pressure in your ears is the roof panel or the floor. Most likely roof.

Now, a comment on the roof. Yes, there is a TSB to re-glue the roof skin to the struts that form cross-members. So, there seems to be a sense that if that bond is intact, then can't be the roof. Here's the thing - how many folks have seen what those struts look like up close in person? I have. I saw mine when it was apart. Those strusts are a fricken' joke. Flimsy as toilet paper. And, large spans between them. I can still see (yes SEEEE) my roof flexing when anything disturbs the body. Even opening and closing the rear doors through the detents. And if I can see it, then it's moving a shit load by vibration standards!!

But what do I know. I just own the thing!!

FogDucker · May 21, 2015

Funny you bring this up Wrench589, while you were typing your last response, I was reading one of those technical documents. This one by a couple of folks at Toyota who specifically looked at 50Hz [bass like] noise in body on frame SUVs.

Body mounts definitely play a role - they even provide the formula to show how!

Modal analysis theory is applied to the body/frame structure mode shape that increases the drive line booming noise at 50 Hz on the body/frame structured SUV, and the following findings have been obtained.

(1) Application of modal analysis theory makes it possible to express the frame mode shape of the body/frame structure with body mount stiffness and natural mode shapes of free-free support frame. With this analytical approach, it is possible to analyze the vibration characteristics of the structure and calculate body mount stiffness necessary for the frame mode control considering its vibration characteristics.

(2) The body mount stiffness calculated from the analytical approach controlled the mode shape of the frame and reduced the body/frame structure vibration response levels. As a result, reduction of the sound pressure sensitivity of the body/frame structure is achieved without increasing mass and cost.

(3) The requirements of the body mount stiffness, which plays important role in body/frame structured SUV performances, to reduce the drive line booming noise were made clear with a simple method at the initial stage of development.

Maybe revised mounts could be the remedy? I wonder if GM looked at this platform with as much detail as the pair in the Toyota paper did. Alright, I know the answer to that. I do wonder if GM will do anything about it.

--

Marc

JohnnyRay · May 22, 2015

I know this doesn't help all of you here and elsewhere who's had this problem, but I joined just to say THANK YOU to all of you for posting this up on this forum. You have saved us a great deal of money and heartache.

We'd been looking at a Tahoe LTZ for about a month, and spent the last week at no less than 5 dealers all over the state of CA looking for the right one. We thought we'd found it yesterday and went to buy it. The dealer made a great deal over the phone of $1,400 under invoice. Within minutes on the test drive we were like "what is that noise?". To us it sounded like a booming, buffeting or helicopter effect that you get with the windows down. Then my ears starting hurting. We got out and both of us had headaches. I think we drove it all of 15 minutes. We were very literally several minutes from purchasing and googled and found this forum. We read some of your posts while sitting in the Chevy dealership! Needless to say, we backed out and drove the 100 miles back home without a Tahoe.

This was a 2015i...so obviously the problem hasn't been fixed. Too bad, because it's a great looking truck.

I hope GM does the right thing by all of you. We've owned several Silverado 2500s and have always been happy with them. Really disappointing to see what GM is doing (and not doing!) with these new SUVs.

Anon2015 · May 22, 2015

Salt water bags would not be increasing the number of modes; however, due to their absorption of low frequencies, any modal response at those frequencies would be reduced in amplitude.

Also, note, modal frequencies are a function room (or cabin) dimensions. While modal response is a form of resonance, it is not the only cause of resonance. The more likely source of the booming/buffeting is from mechanical resonance (drive train, engine, exhaust system, etc). From the work by Wrench, the predicted modal frequencies (derived from the dimensions of the cabin area) are not the problem frequencies as measured.

Edited May 22, 2015 by Anon2015