Denali Ultimate 6.2 vibration

JeffK1 · February 1, 2019

Had the truck at the dealer yesterday for a vibration in wheel and floor. I assumed it was a tire balance problem. Dealer says the vibration occurs when the engine drops to 4cyl mode. I also have the factory cat back system that causes vibration in rear seat. For almost 70k this sucks! Were the NVH engineers out to lunch when they designed this truck? In the past I have put together my own exhaust systems and worked through harmonic vibration problems. I wrongfully assumed that GM had done this work for me. A change in motor mounts and possibly a heavier flywheel might cancel out the 4 cyl problem. It reminds me of a similar problem when the industry started using v6 engines instead of a straight line 6.

Anyone have a similar experience with the 6.2?

OnTheReel · February 2, 2019

I’ve found DFM to be pretty much imperceptible on my 6.2. I don’t get any of the vibrations or odd noises that were all too prevalent on my 2016. But I also have stock exhaust and 20” wheels so you have a few key differences on your rig.

Also worth noting, the engine doesn’t really just drop into “V4” like the K2 (AFM) trucks. It alternates all kinds of patterns. That’s why there’s no longer an indicticator on the dash.

I don’t think I would be satisfied by their explanation as it sounds like the tech doesn’t really know or care.

Chad Sargent · February 2, 2019

Got V8, Never had this problem

BeardBros · February 5, 2019

I have a 2019 high country with 22" wheels, stock exhaust, 6.2L and the 10 speed. Once in a while on a 55mph highway with the cruise control on I can feel a very slight vibration from the active fuel management system being used. The rest of the time it is not even noticeable. I went for a 100 mile straight run on the interstate last Saturday and it was smooth all the way doing 70-80mph.

Keta · February 6, 2019

My Denali ultimate is exceptionally smooth and quiet. Very hard to tell when DFM is activated, every so often I can faintly notice something but nearly imperceptible. Drove 1300 miles last weekend both in town and highway with zero complaints except for the stock Bridgestone tires in snow. BTW this has 22" wheels, 6.2L / 10sp with stock exhaust.

gmdog2 · March 30, 2019

Yes, I have what sounds like a old heat riser spring rattle in my Denali 6.2, I’ve had it in shop 3x now. It’s the motor dropping cylinders and applying a light bit of gas. That’s when mine makes this noise and as soon as it request more power, it disappears.. 2200 miles on it.

I’m going to spray foam the front area!! As GM has told me it’s the nature of the beast. [emoji3061]

I also had foam added to my mirrors because of a wind leak..I should have waited a year!!

But it does run like a beast!!

Drove a new one off the lot, same story..

Sent from my iPhone using Tapatalk

Northeast4050 · May 3, 2019

I've got a 6.2 and also have the performance package with cat back exhaust...I've been noticing the same vibration...its minor but its noticeable and annoying...super frustrating for a 66k truck with 400 miles on it.

Robwcormack · May 3, 2019

This is why I'm impatiently waiting for Range to release the disabler. Says in the coming weeks still on their website which I check multiple times a day along with the borla site for the 6.2 system

Tritipnbeer · May 10, 2019

I also have a stock 2019 Denail 6.2 with Ultimate. If the DFM is coming on I surely can't tell. Feels smooth like butter all the time in all conditions. If the DFM is what is getting me 21.5 MPG on the highway then I'm a happy camper.

CaptKev · May 10, 2019

My 19 Denali Ultimate (2000 mi, 3 weeks old) was back to the dealer for a vibration, they are getting me a loaner next week. They need to swap out tires, they claim they have had issues with the 22" tires being defective. The vibration is not bad (not as bad as my 14 HC) on the highway, but when hitting bumps the truck seems to chatter pretty good. We'll see what they come up with.....

Sierra Dan · May 10, 2019

On ‎2‎/‎1‎/‎2019 at 3:08 PM, JeffK1 said:

Had the truck at the dealer yesterday for a vibration in wheel and floor. I assumed it was a tire balance problem. Dealer says the vibration occurs when the engine drops to 4cyl mode. I also have the factory cat back system that causes vibration in rear seat. For almost 70k this sucks! Were the NVH engineers out to lunch when they designed this truck? In the past I have put together my own exhaust systems and worked through harmonic vibration problems. I wrongfully assumed that GM had done this work for me. A change in motor mounts and possibly a heavier flywheel might cancel out the 4 cyl problem. It reminds me of a similar problem when the industry started using v6 engines instead of a straight line 6.

Anyone have a similar experience with the 6.2?

Jeff, I assume you have a K2 design?

This post is in the new T1 truck section which utilizes DFM not AFM.

Sierra Dan · May 10, 2019

Read here:

CaptKev · May 16, 2019

On 5/10/2019 at 6:28 AM, CaptKev said:

My 19 Denali Ultimate (2000 mi, 3 weeks old) was back to the dealer for a vibration, they are getting me a loaner next week. They need to swap out tires, they claim they have had issues with the 22" tires being defective. The vibration is not bad (not as bad as my 14 HC) on the highway, but when hitting bumps the truck seems to chatter pretty good. We'll see what they come up with.....

They are replacing one bad tire and then we'll see from there. They have had it for half a day, we'll see what today brings.......

CaptKev · May 20, 2019

On 5/16/2019 at 6:28 AM, CaptKev said:

They are replacing one bad tire and then we'll see from there. They have had it for half a day, we'll see what today brings.......

They replaced the bad tire and there is still a problem. I had to take the service manager for a ride today, he is not thinking it's a wheel/tire issue as it vibrates through all speed ranges. I left it with them again. Not happy, brand new truck, 2900 miles, WTF

CaptKev · May 21, 2019

On 5/20/2019 at 2:45 PM, CaptKev said:

They replaced the bad tire and there is still a problem. I had to take the service manager for a ride today, he is not thinking it's a wheel/tire issue as it vibrates through all speed ranges. I left it with them again. Not happy, brand new truck, 2900 miles, WTF

Got the call back today that after all the testing with the specialized equipment, GM says there is a bulletin out that extends to the 2019 GMC Sierra 1500 that as the DFM does it's thing, there may be a vibration felt in the floor, seat, steering wheel, etc. there is no service recommenced! So with 2900 miles on it, and $62K i'm supposed to live with the stupid vibrations. They claim that there is no vibrations when the truck is in manual shift mode and that is the proof that the vibrations are caused by the DFM....

Am I being jerked around, or is this what I am supposed to live with on this truck?

Is there a place to see all the service bulletins online?

I'm pissed that I have a great truck that rides like shit!