2015 YUKON NOISE IN CABIN

FogDucker · October 7, 2015

Marc- Do you not experience the buffeting in your denali? I know I'm late to the party as I have only had my 15 for a month but it seems as though there are two main cabin issues...

1. Buffeting (which I believe has been present in all models from base to denali/ltz)

2. The "boom" sound which seems to be isolated to the denali/ltz with ANC.

Is this accurate? I don't seem to have the Boom sound issue with my SLT....it's actually very quiet with only the annoying and sickening(literally) buffeting/pressure problem.

Yes, my truck buffets. I believe that #1 and #2 are the same issue. Buffeting is repeated booms, at least to my ears. To recap, I experience:

Single instances of "the boom" at low speeds over bumps [driveways, expansion joints...]; coincides when rear wheels go over the bump; sounds like somebody flicking a 12" subwoofer with their finger; doesn't always happen; slightly more difficult to hear; commonly heard on concrete borders between driveways/lots and roads
Repeated instances of "the boom" at speeds of ~65km/h and ~115km/h [40mph and 70mph]; not heard at speeds greater than 130km/h [80mph]; this is the "buffeting"; annoying as hell; sounds like driving with rear windows down; sounds like double bass from a heavy metal band using a broken amplifier; 30-70Hz range; not all the time, but most of the time; some road surfaces seem to excite it more than others; can be heard more clearly when ear is facing rear of vehicle; fades in and out; towing doesn't seem to change the behavior; happens with seats up, down or folded; no crossbars on roof rails [yet]

My Yukon is a stock 2015i short Denali with the only option being the 2nd row bench. No sunroof. 20" wheels with Continentals. 6.2L/8-speed

--

Marc

Willyspu · October 7, 2015

For those of you who are testing things, is it possible the roof is flexing like a large speaker cone making the low frequency booming?

If someone could try sitting in say the 2nd row and pushing up on the roof to steady it, maybe you could feel if it was flexing at speed. The GM TSB that recommended adhering the bows to the roof may have been point to a roof flexing situation.

If that were part of the booming it could be easily stiffened with something like Dynamat.

Meanwhile, my 2016 is built and waiting for transport from Texas to California.

Jim

Edited October 7, 2015 by Willyspu

FogDucker · October 7, 2015

For those of you who are testing things, is it possible the roof is flexing like a large speaker cone making the low frequency booming?

If someone could try sitting in say the 2nd row and pushing up on the roof to steady it, maybe you could feel if it was flexing at speed. The GM TSB that recommended adhering the bows to the roof may have been point to a roof flexing situation.

If that were part of the booming it could be easily stiffened with something like Dynamat.

Meanwhile, my 2016 is built and waiting for transport from Texas to California.

Jim

I forgot to include that in last nights summary - I tried that. No change. I applied pressure to almost every panel with no change.

--

Marc

Edited October 7, 2015 by FogDucker

ajs800 · October 7, 2015

Yes, my truck buffets. I believe that #1 and #2 are the same issue. Buffeting is repeated booms, at least to my ears. To recap, I experience:

Single instances of "the boom" at low speeds over bumps [driveways, expansion joints...]; coincides when rear wheels go over the bump; sounds like somebody flicking a 12" subwoofer with their finger; doesn't always happen; slightly more difficult to hear; commonly heard on concrete borders between driveways/lots and roads

Repeated instances of "the boom" at speeds of ~65km/h and ~115km/h [40mph and 70mph]; not heard at speeds greater than 130km/h [80mph]; this is the "buffeting"; annoying as hell; sounds like driving with rear windows down; sounds like double bass from a heavy metal band using a broken amplifier; 30-70Hz range; not all the time, but most of the time; some road surfaces seem to excite it more than others; can be heard more clearly when ear is facing rear of vehicle; fades in and out; towing doesn't seem to change the behavior; happens with seats up, down or folded; no crossbars on roof rails [yet]

My Yukon is a stock 2015i short Denali with the only option being the 2nd row bench. No sunroof. 20" wheels with Continentals. 6.2L/8-speed

--

Marc

Thanks.

Have there been many reports of the 2016s having the buffeting issue?

FogDucker · October 7, 2015

Thanks.

Have there been many reports of the 2016s having the buffeting issue?

Unknown. That's one of the biggest challenges - sizing the scope of the problem. This forum likely consists of less than 1% of 2015/2016 Yukon/Tahoe/Suburban/Escalade owners. Difficult to spot trends in a forum full of enthusiasts and owners looking for an answer to their problems.

GM would likely be able to report on the number of incidents reported by their dealer network, but us common folk have no way of collecting those kinds of stats.

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Marc

yahtzee · October 7, 2015

I just heard back from one of the publications I've been after. He has direct relationships with GM and wants to drive one that has the issues we are experiencing.

He is going to be in LA, Las Vegas and Detroit in the short term. Anyone here that nearby?

FogDucker · October 7, 2015

Update: I decided to take this up with my local dealership and took the service manager out for a drive. He could "feel" it more than he could hear it, at least from the passenger seat. When he drove it, he could feel it less but hear it. "You've got vibration."

An appointment is scheduled for the end of next week and they'll have it for the day.

@Yahtzee: Nice work getting some attention. Hopefully we can find a volunteer in those cities.

--

Marc

Anon2015 · October 8, 2015

"My Yukon is a stock 2015i short Denali with the only option being the 2nd row bench. No sunroof. 20" wheels with Continentals. 6.2L/8-speed"

For the record, my daily driver is the same but with the sunroom and crossbars.

Wrench589 · October 8, 2015

Thanks.

Have there been many reports of the 2016s having the buffeting issue?

Yes. Owners of 2016's have reported buffeting.

Wrench589 · October 8, 2015

I forgot to include that in last nights summary - I tried that. No change. I applied pressure to almost every panel with no change.

--

Marc

I did the same with the roof liner. No improvement. But, I was only pushing on the headliner, not the roof panel/skin itself. With all the insulation between the headliner and the panel, and how stiff the headliner itself is, I'm not sure how much force actually ended up on the roof skin. There still may be an opportunity to see some improvement with extra stiffening. I will say this - I saw mine with the headliner all tore out for the bulletin repair and the cross struts are a joke. They could not have made them more flimsy if they tried.

TOBTEK · October 8, 2015

If this is what you believe, why not spend the money and get the best shocks on the market?

I've actually did some web surfing looking for better quality, softer shocks and springs. Didn't find anything. Have you seen any that are now available? I'd be happy to pay a reasonable price to make this thing ride better and softer.

Anyone have access to GM parts? Would be interesting to try an older 2010,2011....body mounts if they would bolt in.

FogDucker · October 8, 2015

I've actually did some web surfing looking for better quality, softer shocks and springs. Didn't find anything. Have you seen any that are now available? I'd be happy to pay a reasonable price to make this thing ride better and softer.

Anyone have access to GM parts? Would be interesting to try an older 2010,2011....body mounts if they would bolt in.

I like the magnetic ride. It's just right for highway drives, imho. Firm on on-ramps and off-ramps. I never tried the non-magnetic to compare to, but it's much better than the enclave/acadia/traverse.

100% satisfied of we can just solve the boom and/or vibration...

Wrench589 · October 8, 2015

Yes, my truck buffets. I believe that #1 and #2 are the same issue. Buffeting is repeated booms, at least to my ears. To recap, I experience:

Single instances of "the boom" at low speeds over bumps [driveways, expansion joints...]; coincides when rear wheels go over the bump; sounds like somebody flicking a 12" subwoofer with their finger; doesn't always happen; slightly more difficult to hear; commonly heard on concrete borders between driveways/lots and roads

Repeated instances of "the boom" at speeds of ~65km/h and ~115km/h [40mph and 70mph]; not heard at speeds greater than 130km/h [80mph]; this is the "buffeting"; annoying as hell; sounds like driving with rear windows down; sounds like double bass from a heavy metal band using a broken amplifier; 30-70Hz range; not all the time, but most of the time; some road surfaces seem to excite it more than others; can be heard more clearly when ear is facing rear of vehicle; fades in and out; towing doesn't seem to change the behavior; happens with seats up, down or folded; no crossbars on roof rails [yet]

My Yukon is a stock 2015i short Denali with the only option being the 2nd row bench. No sunroof. 20" wheels with Continentals. 6.2L/8-speed

--

Marc

Your observations are 100% identical to mine. The "buffeting" is a series of "booms".

For those of you fairly new to this thread that haven't read all 80 pages, I previously posted that body "booms" in automobiles is nothing new to the industry. SAE alone has hundreds of technical papers published on the topic, most from the car makers. And SUVs are more pronounced, of course. And, all kinds of methods to control the noises, everything from body mounts to electronic noise cancelling.

I will share another recent observation. I recently had a 2015 Ford Flex rental for a few days. (Awesome vehicle? Btw). Two things I observed. Every morning, I could feel a vibration in the steering wheel that felt like the tires. After 10 or 15 kms it went away. Pretty sure the tires were flatspotting. Now, tire flat spots was not an issue 20 years ago. Why isn't such a common thing now? Low profile tires? Different synthetic rubber compound?

The second observation is this vehicle definitely booms too. Not as severe but it's there. Certain bumps in the road. Same as the Yukon. And, when I hit the highway the tire vibs set up subtle buffeting until the flat spots dissipated. So consistent with all the SAE papers, all these vehicles behave this way to some degree.

Wrench589 · October 8, 2015

Duplicate

Edited October 8, 2015 by Wrench589

The Zip · October 8, 2015

Pretty sure the tires were flatspotting. Now, tire flat spots was not an issue 20 years ago. Why isn't such a common thing now? Low profile tires? Different synthetic rubber compound?

I have a thirty year old car in the in the garage, back in the eighties a 16 in wheel was about as big as they went on passenger vehicles and the tires were made with fabric cord. Today, a passenger vehicle has 22 in wheels as the norm and the tires have evolved with steel belts. Loose or bad belts can cause problems on an otherwise perfect looking tire, may account for what you describe as flatspotting.