GMC Yukon Denali 2016 Vibration problems

[pascalgerber]

I am a proud owner of a GMC Yukon 2016 Denali. Since these cars are not officially available in Europe, I imported a Yukon. Basically, I am very satisfied with the vehicle.

 

But unfortunately, I have a problem with the vehicle, and nobody could help me so far: The car vibrates quite heavily and uncomfortably. The vibrations started when I stopped at the side of the road to let my wife get out. The engine lamp flashed, and the vehicle had hardly any power left. I drove about 1/4 mile, stopped again, and switched off the car. Afterward, I waited for over one minute and then restarted the car. The engine light stayed off, and so I was able to drive on. Also, the power was as usual again. But from there on I had vibrations which I didn't have before.

 

So I went to a service station to read out any errors and get some help. But there were no errors detected. Since the vibrations did not disappear on the next miles, I went to the dealer again. They reprogrammed the ECU unit with the latest software and balanced the tires. Nothing has changed. So I went to another dealer, hoping that it could help me in a better way. They told me that my tires were worn out and that they could cause the vibrations. We changed all four tires. The handling was a bit better afterward, but the vibrations remained.

 

Because in my country there are just about 10 GMC Yukon and a few Escalades driving around, no dealer has a clue and can solve my problem. Therefore I did a lot of research on the internet and on the paid platform of GM (ACDelco TDS) - unfortunately without success so far. 

 

I am also familiar with the service bulletins for the 8-speed automatic transmission. But I can exclude these vibrations so far. I have some of these vibrations in my car. However, I have now imported the right oil from Texas by ship, and I will do the oil change within the next days.

 

But the other vibrations are noticeable at any speed, even at only 1 or 2 mph or over 100 mph. Especially when I ride uphill or downhill, it vibrates a lot. As if I had no suspension in the back and the vehicle would bounce around. The vibrations are mainly felt in the seat. Very slightly also in the steering wheel. From the beginning, my car tends to steer slightly to the left. But I never paid much attention to this, because measuring the track showed that everything is ok.

 

I am aware that a remote diagnosis is challenging. But perhaps you have any ideas where I should proceed with my further diagnosis? Is the suspension the right start, the drive shaft, or the wheel mounting? Or could it be the engine mounting? Or something completely different? What is the best way to proceed?

[Russ Swift]

Two issues I had and how they were resolved.  1.  The transmission torque converter was slipping causing the entire vehicle to vibrate:  Dealer did a transmission service/flush and reprogrammed the engine and transmission modules.  Fixed the problem.  Does it feel like you are driving over railroad tracks...that is how I’ve hear someone describe it.  2.  Both rear shocks were shot, air bags did not hold air so the compressor would continue to try and adjust the shocks.  Would have burned itself out if I didn’t have the rear shocks replaced...does not sound like your problem.  One more thought, make a list of your symptoms (Any sounds, smoke), when they happen (speed, how long driving, temp, ect, ect), where you feel the vibration (Seat, Steering Wheel, ...trying to pinpoint where the problem is coming from.  If at a slow speed have someone outside the vehicle to see if they see or hear anything.  Good Luck.

[pascalgerber]

Thanks Russ for your post. I will do the transmission flush and reprogramming in the next few days. But I 'm not that sure, if the ttc shuddering causes the vibrations in my car since my car vibrates at any speed. But you are right, I have this ttc shuddering sometimes and when it appears it feels like driving over railroad tracks. The rear shocks could be a problem. But I could rather imagine that they get stuck in the outermost position as soon as the car is moving. That would also explain the feeling that I have no suspension in the back of the car. As far as I can tell, the compressor works as desired.

 

Good point with the list:). I made one a few weeks ago, it is quite simple: vibration at any speed, no smoke or rattling or noice or similar. No parts that are visually not moving round.

[Doug B]

I have a 2012 GMC Yukon Denali SUV, 6.2 Litre.  I have a vibration mostly under torque or acceleration. if you take your foot off the gas it stops.  Sounds a bit like Russ's issue - the vibration is more like going over railway tracks.  I have changes U joints, ball joints, tie rods i beleive, drive shaft.  Now garage thinks maybe transmission/torque converter.

 

Any thoughts keep paying for nothing - i have had to 2 seperate garages.