2017 Denali fluttering when accelerating. VIDEO

[Tahoedrivingmom]

Thank god I'm not crazy! I've had my 2017 Tahoe Z71 in the shop 6 times since May, trying to get them to find the source of the issue. The service technicians all insist that they didn't hear it. After picking it up for the final time this past Friday, they told me the GM engineer said it was a completely normal noise that occurs when it switches from V4 to V8. I cannot believe that I spent this much money on this vehicle for it to sound like it has a huge exhaust leak. Surely GM will find a fix for this. This was my first and will for sure be my last General Motors vehicle I ever purchase. Very poor quality.

 

[jeffbco]

Does it go away when you disable AFM? You can check by putting transmission in "M" or "L" and advance the gear selection to 5. It will shift normally through 5 and AFM will not be enabled. If so you might want to try the "$1 fix" described here:

http://www.tahoeyukonforum.com/threads/the-1-00-cat-back-mod.65748/#post-825530

 

[dbbd1]

Does it go away when you disable AFM? You can check by putting transmission in "M" or "L" and advance the gear selection to 5. It will shift normally through 5 and AFM will not be enabled.

OT

But thanks for that quick tip on disabling AFM. It'll be handy to know...

 

[Nashoba]

I have been playing with the M5 disabling of the AFM for a couple of weeks now. It makes driving in town so much smoother. I have not tried it above 40 mph as the highest speed limit in our town is 35. And when on the highway, i want AFM activated for the higher mile age benefits. We have this on our 2008 Tahoe Hybrid and it is nearly invisible/undetectable during normal operations. The engine stop feature is far more noticeable than any other feature. And during operation, the change from engine to electric motor and back the other way is virtually undetectable. On my 2015 Silverado, the AFM is very evident while in town but has been slick and smooth on the road. I have not detected any "flutter" in either vehicle, just a direct change when the AFM functions at low speeds. But, once again, perhaps my age effects what I notice. Having learned to drive in a pasture filled with buffalo "wallows", in a 1949 Studebaker pickup when I was six, I look back and find the complaints about today's vehicles to be relatively minor compared to some we had to deal with back in the day.

 

[Sjp45066]

Does it go away when you disable AFM? You can check by putting transmission in "M" or "L" and advance the gear selection to 5. It will shift normally through 5 and AFM will not be enabled. If so you might want to try the "$1 fix" described here:

http://www.tahoeyukonforum.com/threads/the-1-00-cat-back-mod.65748/#post-825530

It's not the AFM in my case either. I've tried the M5 trick. The sound is there like an exhaust leak when the engine is around 1200-1700 rpm and slight acceleration is applied. And as I stated in an earlier post, this only happens after the engine has reached normal temperature. When cold, there is no sound and everything is smooth. I strongly suspect it's the torque converter/transmission. I plan to take it to the dealer again soon.

 

[Tahoedrivingmom]

It's not the AFM in my case either. I've tried the M5 trick. The sound is there like an exhaust leak when the engine is around 1200-1700 rpm and slight acceleration is applied. And as I stated in an earlier post, this only happens after the engine has reached normal temperature. When cold, there is no sound and everything is smooth. I strongly suspect it's the torque converter/transmission. I plan to take it to the dealer again soon.

If you don't mind, let me know what they tell you. This is the exact problem I have and am getting nowhere with the dealership.

 

[mtocrs1]

I have the same issue on my 15. It has been there since new although I can only hear it with the windows down. Additionally it can not be heard by bystanders, only heard from inside the vehicle with window down. I to suspect the transmission as I have had a surge on acceleration since new as well, the surge is much more prominent when the ambient temperature is lower.... The surge can be so bad it makes everyone look like some kids from the late 90's jamming to Nirvana. Its either low line pressure or torque management. One day I will see if a tune takes care of it.


Sent from my iPhone using Tapatalk

 

[GTNator]

I gave up and got rid of mine after 1 year. The money and time isn't worth my sanity. No more GM vehicles for me. After 1 year it was literally rattling everywhere and the plastic creaked horribly. Not acceptable for a vehicle over $70,000. The ride grew rougher as time passed and it was very uncomfortable at 9600 miles.

Mine was paid for, so I got a 2017 Toyota Tacoma Limited and a check for my remaining equity. When I took the Denali over railroad tracks I literally thought it or I was going to fall apart. So harsh. The Tacoma rolls over bumps with ease. It is amazing to me that a vehicle that cost 40,000 can feel so much better than the Denali.

I've always preferred the appearance of GM vehicles. They do great there. Customer service, reliability, durability, and quality control, well apparently those things didn't exist with my last two GM vehicles.

Wow, that's bad.


Sent from my iPhone using Tapatalk

 

[jlbravo]

Picked up a 2017 Denali just over a month ago, been hearing a "fluttering"/rattling type sound when accelerating. I'd say it usually happens at about 1500-1700 RPM... occurs when you're asking for a little more speed and usually stops when at cruising speed.

Dealer said it's the sound of some exhaust valve with the purpose of keeping the muffler quiet... is this normal? Seems too loud to be normal. Video attached.

I am having the same issue, was there any solution to this? I have a 2017 tahoe

 

[Sjp45066]

I am having the same issue, was there any solution to this? I have a 2017 tahoe

I took the Tahoe in to another dealer. They kept it 3 days and researched all of GM’s service bulletins. I got it back with an all new exhaust system. As expected, it did nothing to solve this issue. I had even told them I don’t think it’s the exhaust. I don’t think the dealers know how to fix this.