Vibration

[Douglas L Self]

I have a 2020 GMC Sierra 1500 5.3 with less than 12 K miles I have had it in for the problem 3 times. I am told there is nothing that can be done to correct it. Here is the problem,  at any speed (especially highway speeds) a vibration occurs frequently, it only last a few seconds but a mile or so down the road it will happen again. This happens on flat roads hilly roads and can really be felt on smooth roads. The last time I had it in the service department they said it is happening when the engine changes from 8 to 4 cylinders and back to 8 cylinders and that there is nothing that can be done to correct it. It is hard for me to believe that GM has built a vehicle with a very annoying problem and it can’t be corrected. I am thinking seriously about putting signs on the truck that says (DON'T BUY GMC TRUCKS THEY CAN'T FIX PROBLEMS WITH THEIR MOTORS). I paid way to much for this truck to have to have to go down the road with it vibrating and shaking, very annoying!! Anyone else have this problem and does anyone have a suggestion how to correct it?

[EricTheRed]

You can disable the DFM with the Range device.

 

https://www.rangetechnology.com/products/afm-dfm_disabler/

Edited September 21, 2020 by EricTheRed

[Hensonz]

I have a 21 AT4 with a 5.3 DFM with 4500 miles on it. I have had mine to the dealership twice and they told me the same thing about mine. I called GM and reported it, now I’m waiting to hear back from them. Hopefully they will help. 

[voided3]

It sounds like normal AFM/DFM operation to me. I run our DFM-equipped 5.3 in L7 (8-speed transmission) to disable DFM and it's a much smoother, better driving experience. I still get 21 MPG on the highway in 7th gear (3.23 read end) so you do lose about 1-2 MPG, but not bad.

[It's Tim]

Why is everyone so quick to blame the manufactuer when EPA/CAFE mandates caused this? 

[Kyle Ross]

The way i see it is they're pulling your leg. GM has had cylinder deactivation for years now and haven't ran into that problem. There are many tsbs and have ran into many low mile gm truck having motor mount issues. Along, with torque converter problems that causing vibrations  

[shakenfake]

46 minutes ago, It's Tim said:

Why is everyone so quick to blame the manufactuer when EPA/CAFE mandates caused this? 

Because the manufacturer builds and makes the design not the EPA/CAFE. 

 

Also I believe you are incorrect, GM did this to help the fuel economy back in the early 2000s, no mandates caused them to create cylinder deactivation. They were looking for ways to try and keep fuel economy good on trucks and SUVs to keep up profits. 

 

Interestingly enough though this started in the 70s in a Cadillac and the whole idea was scrapped after a year because it was so difficult to keep functioning. Nowadays it works but it is still a weak point. In the 70s it was actually a gasoline mandate that caused them to start thinking this way.

 

 

https://www.hagerty.com/media/archived/gm-pioneered-cylinder-deactivation/

[Rob133]

Was having the same issue and was diagnosed today with a torque converter problem and they are warranting me a new one. Search up TCC shutter on here. Theres other possible fixes for this

Edited November 5, 2021 by Rob133
Typo

[RICHARDBROWN1]

I have a 2021 5.3 8 speed I have a vibration between 24&28 mph GM installed a new transmission replaced U joints a new driveshaft 2 new rear ends still have the vibration they told me it’s just something I will have to live with 

[4threeking]

I have the same exact issue. If you guys want to keep the factory blocks just order 2.5 degree shims. This will angle the rear diff so the pinion on the drive shaft is inline with the transmission. Chevy should have these included but it took me forever to figure out the issue

https://amzn.to/3pbzmdj

 

Throw these on your rear leaf springs and point the narrow end towards the front and the thick end towards the back. that should fix the issue.

Edited June 23, 2023 by 4threeking

[loinse bekean]

GMC and other automotive manufacturers often release Technical Service Bulletins for common issues. Check with your dealer to see if any TSBs related to your problem exist and if they have been applied.

wordle

[Transient]

On 11/4/2021 at 9:33 AM, shakenfake said:

Because the manufacturer builds and makes the design not the EPA/CAFE. 

 

Also I believe you are incorrect, GM did this to help the fuel economy back in the early 2000s, no mandates caused them to create cylinder deactivation. They were looking for ways to try and keep fuel economy good on trucks and SUVs to keep up profits. 

 

Interestingly enough though this started in the 70s in a Cadillac and the whole idea was scrapped after a year because it was so difficult to keep functioning. Nowadays it works but it is still a weak point. In the 70s it was actually a gasoline mandate that caused them to start thinking this way.

 

 

https://www.hagerty.com/media/archived/gm-pioneered-cylinder-deactivation/

Check your history.  You're correct about the 70s oil embargo and Cadillac's failed cylinder deactivation failure.  However, you're incorrect about modern day reasons for cylinder deactivation.  EPA has been a thorn for many decades, and the reason for killing off many good engines.  They liked off the supercharged 2.0 ecotec, which brought forth the turbocharged 2.0 ecotec.  A little less than 20 years ago oil prices skyrocketed, and so to did gas prices.  The big 3 were hit hard with a sudden decrease in large vehicle sales.  It pretty much killed off Hummer.  The large vehicles are the core of the companies profits.  That's when GM brought back cylinder deactivation, called Displacement on Demand.  Iirc, model year 2007 was the first year of it.  They also gave the vehicles the ability to use e85 gas.  Your gas cap being yellow was your indicator if your vehicle could run on e85.  Imo, both attempts were an epic failure.  E85 is a joke, unless you are running a high performance car tuned and modified to take full advantage of it.  As for DOD, the first iteration shut off the fuel injectors, but kept the valve opening and closing, which led to scorched oil, to worn piston rings, to excessive oil consumption, then destroyed bottom ends of the engine.  However, there was never a vibration until the bottom of the engine went.  MY2014 or MY2015 brought the first improvement to cylinder deactivation with a redesign of the heads, marketed as Ecotec.  Still no vibration though.  I now have over 53,000 miles on my 2020 Silverado with the 6.2 and have never experienced a vibration with this truck.  If the vibration came from cylinder deactivation, that thread would be way bigger than the leaking rear window thread.  Nonetheless, the EPA and CAFE regulations have been a driving factor behind the cylinder deactivation.  It is GM's way of ensuring V8s stay in trucks.  GM and Nissan are now the only 1/2-ton trucks with V8s.  It doesn't look like Nissan may be in the 1/2-ton segment much longer.  Ram just debuted its next generation of truck and they're replacing the V8 hemi engine with an I-6 turbo.  Oh, and the Ram REV is a play right out of GM's playbook.  It's a truck version of the Chevy Volt.  At this point, everything we don't like regarding the direction trucks are going is due to EPA and CAFE.

[Orabelle]

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[pepelu]

GMC and other automotive manufacturers often release Technical Service Bulletins for common issues. Check with your dealer to see if any TSBs related to your problem exist and if they have been applied. freechat

Edited April 27 by pepelu

[J OBrien]

On 9/21/2020 at 4:47 PM, Douglas L Self said:

I have a 2020 GMC Sierra 1500 5.3 with less than 12 K miles I have had it in for the problem 3 times. I am told there is nothing that can be done to correct it. Here is the problem,  at any speed (especially highway speeds) a vibration occurs frequently, it only last a few seconds but a mile or so down the road it will happen again. This happens on flat roads hilly roads and can really be felt on smooth roads. The last time I had it in the service department they said it is happening when the engine changes from 8 to 4 cylinders and back to 8 cylinders and that there is nothing that can be done to correct it. It is hard for me to believe that GM has built a vehicle with a very annoying problem and it can’t be corrected. I am thinking seriously about putting signs on the truck that says (DON'T BUY GMC TRUCKS THEY CAN'T FIX PROBLEMS WITH THEIR MOTORS). I paid way to much for this truck to have to have to go down the road with it vibrating and shaking, very annoying!! Anyone else have this problem and does anyone have a suggestion how to correct it?