2015 YUKON NOISE IN CABIN

[Elripster]

My bows came over of the course of weeks. I suppose you could try that and see how it works. That really is the only way to know, by trying it.

 

Maybe the best approach is to get the bows fixed and then install it right away to keep them attached?

 

Frank

[boazEarl8]

My bows came over of the course of weeks. I suppose you could try that and see how it works. That really is the only way to know, by trying it.

 

Maybe the best approach is to get the bows fixed and then install it right away to keep them attached?

 

Frank

 

Right, only right after the GM "fix" is applied. Maybe I'll give it a shot.

[sas06]

Guys,

 

I seriously think the problem lies in the hatch door. The buffeting in my car was coming on and off on the same roads on different days. That was because sometimes the door is properly closed and other times it is not. Last night I observed it clearly. I drove with my friends to the city and it was buffeting like hell. My friends noticed as quite bothersome. Then, I opened the hatch door and slammed it hard. After that buffeting disappeared (or at least 80% of it), and it all felt like normal, even driving on the same roads.

 

I believe if the rear hatch door is adjusted properly, seals are fixed, and vibrations from wheel are fixed then buffeting should disappear, or at least most of it should disappear.

[Ozzii]

What do you think is causing the booming noise when driving over bumps in the road? Im not suffering from buffeting at highway speeds, just the ear pressure and the booming.

Edited January 20, 2016 by Ozzii

[FogDucker]

What do you think is causing the booming noise when driving over bumps in the road? Im not suffering from buffeting at highway speeds, just the ear pressure and the booming.

That *could* be related to the hatch as well, IMHO. The hatch might be bouncing down into the opening of the truck as it bounces up over the bump. I thought I had improved it with my foam experiments, but I couldn't reproduce it. The booming is prominent when driving over snowy roads.

 

Adjusting the stops on the hatch can also make the buffeting better/worse. I wrapped them in painters tape and make 1/2 turn adjustments at a time.

 

My Yukon will be going back to the dealership soon for a close examination of the hatch and the seals. Among other things. I'm sure they've got better ways of ensuring proper fitment.

 

My experiments are on hold because it's gotten cold and I have had little time. Though I did try removing the amp fuse (#48 on passenger side) last night to rule out ANC. It made no difference to the buffeting.

[yahtzee]

Just posted the survey in the Facebook group.....fyi.

[Booty]

Guys,

 

I seriously think the problem lies in the hatch door. The buffeting in my car was coming on and off on the same roads on different days. That was because sometimes the door is properly closed and other times it is not. Last night I observed it clearly. I drove with my friends to the city and it was buffeting like hell. My friends noticed as quite bothersome. Then, I opened the hatch door and slammed it hard. After that buffeting disappeared (or at least 80% of it), and it all felt like normal, even driving on the same roads.

 

I believe if the rear hatch door is adjusted properly, seals are fixed, and vibrations from wheel are fixed then buffeting should disappear, or at least most of it should disappear. AMEN sas06, I hope they listen to you. I have known this all along and no one listened . They would rather rip the interior out, yank the exhaust off, putty/caulk the roof, buy off brand tires and wheels, mess with the radio, yank fuses out, pull out the drive shaft, rip out the rear end , disconnect the air line from the new shocks, replace the shocks with aftermarket junk, pull the fenders off and add supports, re flash the transmission, and even tamper with the motor on a $70,000.00 brand new car. Geeze Louise !!! Unbelievable........... All the best, Booty

Edited January 20, 2016 by Booty

[FogDucker]

AMEN sas06, I hope they listen to you. I have known this all along and no one listened . They would rather rip the interior out, yank the exhaust off, putty/caulk the roof, buy off brand tires and wheels, mess with the radio, yank fuses out, pull out the drive shaft, rip out the rear end , disconnect the air line from the new shocks, replace the shocks with aftermarket junk, pull the fenders off and add supports, re flash the transmission, and even tamper with the motor on a $70,000.00 brand new car. Geeze Louise !!! Unbelievable........... All the best, Booty

 

To be fair, GM did mostly eliminate my vibration issues by replacing 2 tires, road force balancing them all (twice) and replacing the rear axle.

 

It's the buffeting that hasn't been fixed. And the hatch is now a target for examination...

Edited January 20, 2016 by FogDucker

[Ozzii]

Please keep us posted if you find anymore info on the rear hatch ;)

[boazEarl8]

Thinking outloud

 

If the rear hatch was the true source of the issue, don't you think GM would have fixed that by now almost 1.5 years after the initial reports

 

It would not be expensive for new bushings, tighter couplings, new lock, etc

 

The roof, OTOH, is a major repair expense and even more so if you want to redesign it mid production

Edited January 21, 2016 by boazEarl8

[sas06]

I should also say that:

 

For me as the buffeting has been varying from time to time, it also has been varying from speed to speed, disappearing and reappearing at various speeds. This too can be caused by varying situations of the rear hatch.

 

I have played with door stoppers as well as felt pads. Each change of circumstances changes the level of buffeting and the speed at which it occurs. Last few days I roamed in the city trying to find roads where buffeting does not happen. I found one recently built. This road is super smooth with almost no imperfections. There is almost no buffeting on this road even at very high speeds. I think as the rear of the car (being extra long) shakes/vibrates due to imperfections on the road the hatch may not be able to hold to its strength causing the buffeting to occur. Felt pads are no solution as they tend to leave room in between doors. One should get the seals fixed and the door adjusted.

 

As FogDucker has said, the booming and buffeting both seem to be caused by the hatch. But I would still not completely discount some role played by the roof sheet of metal. As Frank has reported a fix earlier. I would say it could be either one of these issues or it could be a combination of both. But hatch should be a starting point of investigations.

Edited January 21, 2016 by sas06

[Jbardram]

Have to say if media reports, including this forum, are correct about the quantity of suv examples that consistently exhibit these problems, then GM must already know the cause of the problem. They've had ample time and certainly have the engineering resources to figure it out. This isn't some anomalous electrical gremlin affecting a handful of vehicles.

 

Think the real issue is whether they feel compelled to put what is likely a costly fix into production or want to band aid the affected owners/units until a mid cycle redesign.

[FogDucker]

I think that GM has been barking up the wrong tree, confusing buffeting with vibrations. They're looking at it as if it's the same problem and I don't think it is.

 

When I first reported the buffeting to my dealership 3 months ago, they declared that I had vibrations. I didn't disagree. A few visits, parts and picoscopes later, my vibrations are 99% gone. My Yukon is smooth right up to 90mph. The vibrating, it turns out, has nothing to do with the buffeting. They may have incorrectly assumed that the vibrating was causing the buffeting.

 

The biggest challenge with the buffeting is that not everyone can hear it and even if they can, everyone will interpret the severity differently. Everything from "Holy sh!t, my ears are bleeding and my head is going to explode!" to "Whatever, it sounds like we're in a tunnel." Very subjective. Then add the fact that it's prominently heard only in the driver's seat, only at 2 speeds [40mph and 70mph]. Then add the fact that there doesn't seem to be any consistent or cost effective way to measure buffeting either, at least that I've found.

 

The fact that my dealership and GM field engineer(s) are still actively working on trying to resolve the buffeting tells me that they don't know what the root cause is. If it really was an expensive fix, they would have told me to pound salt or agreed to take my truck back. It's possible that they've had the wrong people working on the issue - drivetrain specialists instead of noise & vibration specialists. It's also possible that GM doesn't have the right tools or expertise to properly diagnose this issue. All we can do is speculate because we have little or no visibility into how GM is managing the buffeting issue. Well, speculate and MacGyver with our $70K trucks, pulling fuses, removing panels, removing spare tires, manipulating seals, adding Dynamat to our roofs... If anything, we are a persistent bunch that really like our trucks and want them corrected! I sure as hell do!

 

That's why I think it would be totally awesome to have an expert in vehicle aerocoustics get involved. PhD grade that has spent years living and breathing this kind of stuff. Someone like Franck Pérot from EXA.

[Booty]

I think that GM has been barking up the wrong tree, confusing buffeting with vibrations. They're looking at it as if it's the same problem and I don't think it is.

 

When I first reported the buffeting to my dealership 3 months ago, they declared that I had vibrations. I didn't disagree. A few visits, parts and picoscopes later, my vibrations are 99% gone. My Yukon is smooth right up to 90mph. The vibrating, it turns out, has nothing to do with the buffeting. They may have incorrectly assumed that the vibrating was causing the buffeting.

 

The biggest challenge with the buffeting is that not everyone can hear it and even if they can, everyone will interpret the severity differently. Everything from "Holy sh!t, my ears are bleeding and my head is going to explode!" to "Whatever, it sounds like we're in a tunnel." Very subjective. Then add the fact that it's prominently heard only in the driver's seat, only at 2 speeds [40mph and 70mph]. Then add the fact that there doesn't seem to be any consistent or cost effective way to measure buffeting either, at least that I've found.

 

The fact that my dealership and GM field engineer(s) are still actively working on trying to resolve the buffeting tells me that they don't know what the root cause is. If it really was an expensive fix, they would have told me to pound salt or agreed to take my truck back. It's possible that they've had the wrong people working on the issue - drivetrain specialists instead of noise & vibration specialists. It's also possible that GM doesn't have the right tools or expertise to properly diagnose this issue. All we can do is speculate because we have little or no visibility into how GM is managing the buffeting issue. Well, speculate and MacGyver with our $70K trucks, pulling fuses, removing panels, removing spare tires, manipulating seals, adding Dynamat to our roofs... If anything, we are a persistent bunch that really like our trucks and want them corrected! I sure as hell do!

 

That's why I think it would be totally awesome to have an expert in vehicle aerocoustics get involved. PhD grade that has spent years living and breathing this kind of stuff. Someone like Franck Pérot from EXA.

My thoughts are: The hatch is positioned to the body by robot. Then the human worker installs the bolts, then somewhere down the line the gasket is installed, the hatch is closed and the car moves on down the line. The hatch is large in area (big drum) and is exposed to lots of air pressure. So with a lousy weak seal/gasket and a misaligned hatch and latch you will get the drum affect in your ears. I do not know why my hatch is tight and others are not tight ? Are there 2 robots that place the hatches to the bodies ? And one is calibrated different in the positioning spec ? Is there a real inspection on the closing of the hatch or " Yep, she closes she does, she does" "Move her on down the line boys " Hee Haw type of inspection ? Maybe our GM "line experts" will respond with an answer. With best regards, Booty

[sas06]

My experiences of today:

 

I went to back of my car opened the hatch and started looking at various places in detail. I noticed that the hinge on the right side did not seem symmetric to the ones on the left in terms of how they were joined. The positions of the bolts were slightly different. Upon a more careful inspection I found that the hatch was leaning down from the right side slightly (not easy to notice though). I could also point out the impact point of the hatch to the body on the right side (at the bottom of the hatch), some paint has also been damaged there.

 

Then I opened the door stopper of the right side as much as I could and also opened the left one but only slightly.

 

Upon driving I noticed considerable change in conditions as follows:

 

1. Booming was now less bothersome to the ears. It certainly lessened. I am not completely sure whether it was because the cabin was now less air tight or because the hatch now didn't made the impact on the body.

 

2. Also noticed that the road noise was slightly more than before. This can be certainly due to the fact that the cabin is now not as air tight and noise can easily come in.

 

3. Buffeting also kind of lessened and changed as well. What I noticed was that while driving when the speed of the car stabilizes to say 110 Kmph and stays there. At this point as soon as there are sudden imperfect road conditions the buffeting happens for a while and then subsides and so on. I guess the hatch could now be a bit more shaky on rough surfaces due to road impact.

 

But if people believe that had the hatch been the only problem, GM would have fixed it long ago and the problem is actually deeper... THEN ... my theory is that the cabin in these cars may not be balanced/symmetric in such a way that the hatch finds it hard to settle down and buffets. I hope my theory is wrong because if it is the problem with the cabin itself then it may not be fixable.