sas06

Friends, I am coming back to this forum after a long time. The main problem of buffeting lies in the tires. Just replace them with a good quality soft tires, have them balanced properly and the major issues will be gone. However, in winter when the tires become hard some level of buffeting might still occur, that too in the morning when you start off. May be you need to replace tires a bit more often than with other cars too. Looks like the wheel-base is very sensitive to tire conditions for these cars (suburban etc). It is really an enjoyable car once major issue is gone.

Congratulation FogDucker! I am going to take a print out of your success story to my dealer. Happy to know that there is a fix.

Interesting Findings Below. I hope this will help: 1. I found a 2015 Suburban LS a few days ago which had no buffeting. Very comfortable ride. Did not remember to test booming but will go again to test that. The only difference between this car and my 2015 Suburban LS was the touch screen interface. My car has touch screen that car did not have it. 2. I probably found the cause of booming: If you hit the rear tire with something hard or punch it you will hear resounding going through the body. Now sit inside the car, close the doors, and ask someone else to hit the tire. You will hear the same boom as you hear while driving. So this boom is the resounding in the wheel base occurring from the impact of the tires on the bumps on the road. This can be reduced if the tires are soft but will be very noticeable if they hard. That is why after you have driven miles and tires become softer and warm then booming reduces considerably. If the tires are bad they can be changed but if the whole wheel-base is like that then... 3. There could be several types of buffeting and all could be present at once. Read below. 4. One type of buffeting is due to the strong wind passing through the hollow plastic panels just above the rear lights. These panels are loose and move as well. My dealer used silicon to close inlets into the panels and also made them hard to move. This noticeably reduced cabin noise. 5. If the tires or the wheels are not round then buffeting will occur. The fact that the car buffets at particular speeds and that buffeting speed is different for different cars definitely points to the bad tires or wheels. In my case buffeting occurs more after the car has been parked for long time in cold and then subsides when the tires become soft after driving miles. This is because at night the tires become tough and the parking leaves a flat spot on the tires. Inflating the tires a bit over the 35psi really helped me reduce the buffeting. But tires as well as the wheels should be strictly checked for roundness. 6. The hatch, if it moves, can also cause buffeting. In one case I saw a car going through uneven places and the rear hatch would actually move side ways. No wonder it moves on rough roads and the friction between the door stoppers and the car's body may generate noises. I solved it by putting one felt pad on the door stopper and the other at the spot where the door stopper touches the body, so that the two pads are now super-imposed on each other. This would certainly reduce the hatch noise but the best is to get the hatch properly tightened. My car now drives much better, it does not buffet too badly. It actually is bearable now. But I still need the wheels and tires to be checked for roundness. And I don't know if the booming can be solved. Good luck!

FogDucker! Yes I do mean the hinges on top of hatch (the two hinges on left and right). They are not symmetrically attached. Photos won't reveal much due to minute nature of differences in the two hinges. In response to your towel test I think that booming is due to the roof sheet instead of the hatch, and hatch is only responsible for buffeting. Imagine being in an airtight container and then any flexing in the roof sheet will hurt the ears and create booms. The roof sheet is very flimsy. On top of second row seats it is so thin that you can press it down with one finger without much force. When I opened the rear hatch door stoppers the booming subsided probably because the cabin is not as airtight as before. But that is not the solution as opening the door stoppers increases the road noise. If you open them just enough to make the hatch a bit tighter you can affect buffeting. Buffeting may subside or go away at certain speeds or re-appear at certain other speeds. As you are telling that buffeting in your case appears at 40 - 50, makes me think that your hatch door is more loose than mine as in my case the buffeting only happens at 110+. Tomorrow I am going back to the dealer and putting the car in for checking the hatch. I also might suspect that the rear axil might be producing some vertical vibrations, which in turn may excite the hatch a bit too much.

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.

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.

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.

I am happy to report a success. A few weeks back I noticed that buffeting was worse at times and was quite tolerable at other times and almost went away at some other times. Some participants on this forum have also noticed this behavior, and some also have suggested problems with the rear hatch. I noticed that the metal sheet of the hatch was coming in touch with the metal of the body, which shouldn't happen. At a couple of spots the paint was also coming off due to friction. So while driving, the vibrations in the hatch were causing it to continuously make low intensity impacts on the metal sheet of the body, which caused buffeting at low and high speeds. To solve this, there is a stud made of plastic on the hatch that can be opened/closed like a screw. This can be adjusted to allow some leeway so the hatch metal does not touch the body. So I opened it as much as I could. The door now requires more force to close but it is now stiffer and does not flex if you try to shake it with hand. Then I test drove it and the there was noticeable improvement. The buffeting was reduced to much tolerable level at high speed and low speed buffeting was almost gone. But I must admit that the low speed booming is still there and there is still some level of buffeting at high speed. However, the adjustment took the edge off. I think the remaining part of the solution lies in checking the metal sheet at the roof to see if it is attached to the bows, and putting some dynamat in the roof to support it. I believe it flexes at high speed and contributes to the buffeting. Good luck.

In my suburban LS 2015, I had vibration and buffeting. After changing tires and hardwork on trying to balancing the wheels the vibration went away. This certainly reduced the buffeting from extremely annoying level to much more acceptable level. Now it occurs mostly on certain roads with certain imperfections that sends ripples through the body. It is well known and noted in edmunds reviews (http://www.edmunds.com/chevrolet/suburban/2015/suv/rating/2/) that only tiny little imperfections on the road will be noticeable in the body. I drove with the mechanic sitting with me and he had a pretty good idea of which roads were bad for the car and which ones were good. He asked me to drive on certain roads and told me in advance that the buffeting would happen and it actually happened. Then he asked me to drive on certain other roads and told me that buffeting will not happen on those roads and it did not happen. His explanation is that the rear of the car is light, and when coupled with light and sensitive suspension on these cars the body goes into certain pattern of vibrations due to certain road imperfections that sounds like buffeting. However, I think this could also be due to thin and not very well supported sheet on the roof as other fellows have suggested in this forum. Perhaps the road conditions and vibrations make things worse and more noticeable. Removing vibrations seems to have improved the situation a lot. When I bought it, it was a horrible car, spent sleepless nights due to it, but now the car drives much much much better and buffeting it not a major concern anymore. Perhaps I might live with it. However, will love to try a solution to the buffeting.

I plan to show this post (http://www.gm-trucks.com/forums/topic/153186-shake-or-vibration-issues/?p=1696430) to the dealership and see if they can do picoscope and ring and pinion adjustments. Will probably take a while but will report back. Car has to be sent to a different city for body work.

I am in Saudi Arabia. Bought a Suburban 2015 a few weeks ago. It had horrible vibrations and buffeting noise in cabin. Went back to the dealers and they said the tires need changing. Originally it had Bridgestone tires and they replaced with Pirelli and balanced them. There was huge improvement. The horrible vibrations went away but the buffeting sound is still there, although the sound has reduced somewhat considerably and is far less horrible. One more thing is that I feel ripples going through the body and steering wheel from tiny imperfections on the road. Once I was driving on a newly constructed carpeted and extremely smooth road, and as soon as I got on it all the noise and ripples went away. As soon as I got off they came back. So the buffeting is definitely from some kind of vibrations. I would appreciate if someone could tell what can fix it or reduce it further. My hunch is that the ripples in body could be from drive shaft. A mechanic at the dealer told me it is due to larger wheel sizes. However, I must say that driving long on this car is far less tiring than driving on my 2013 Tahoe, except that one has to bear the noise. So in some ways I love the car also. I have noticed also that slightly reducing the air pressure in tires seems to help in noise reduction but not a lot.... cheers!