AFM vibration in V4 mode

Sierra Dan · January 17, 2019

16 hours ago, dspar00a said:

Mine are in the floorboard and foot pedal mostly. But, not at 1500 or higher. For me, it's 12-1300 and lower.

Do you know if there is a fix for this? It has made me consider trading and going to another brand. I love this truck and have always been a GM person. But, I don't want to go get into another truck and it be the same story. Nor, do I really want to have to go get back into another loan if this problem can be fixed.

There is a thread on it somewhere...… no fix as of yet.

Conspiracy theories include harmonic exhaust vibration, torque converter problems and a couple of other guesses.

Trnr1995 · September 15, 2019

On 1/16/2019 at 1:12 PM, dspar00a said:

I have had tons of issues with my Sierra since I have purchased it. I have had vibrations/shift issues from day one and had my truck in the shop 6 times now to always be told what I am experiencing is normal. My issue always comes from switching from V4 to V8 and it is either a slam like shifting up or down into gear or if in V4 and at a constant low speed. The truck acts as if it has shifted up to 6th gear at 35-40mph and vibrates as if it's about to die. My RPM's drop usually below 1,000 and it's just too high of a gear for that range.

My frustration that my dealer just refuses to act like there is anything abnormal with it. It's bad when my passengers ask if my truck is fixing to break down. I took so outside clients from my work out to lunch one day and they were all worried we were going to have mechanical issues. I just don't think that's normal and if it is, why would GM want this for their $40,000+ vehicles? My brother has the same truck as I but a 15' and his is 100% more smooth than mine. The only fix I have found is driving in M5. It's like a whole different truck.

Any fix yet? Just got truck back from getting new lifters, cam etc. Truck ran great before collapsed lifter. Now new parts and it vibrates and shudders between 45 and 60.

High Country 6.2L/8 · September 22, 2019

On 10/11/2016 at 8:14 AM, silveradosid said:

i also have the v4 vibration and it doesnt matter what speed i am doing, if it goes into v4 mode the vibration starts. what sucks is this truck ran perfectly smooth until it 50k kilometers. then the vibration started and now at 60k it is getting worst and of course the stealership says they dont notice anything different

Did you get the issue fixed? Myself have a 17 High Country 6.2L I went to dealership and they did a triple flush and I dumped the factory shit with Amsoil ATF and dumped all other fluids and switched to Amsoil. I've never had any issues but it only has 31,000 kms.

silveradosid · September 24, 2019

no never did resolve the vibration, even after putting a new exhaust system on. i bought a programmer and turned the afm off . there is a slight change in fuel mileage but no more vibration

JFREED · November 5, 2019

I have been having a similar issue, seems to be after v4 to v8 and under 2000rpms with the greatest noise being at 1100-1300. The rpms fluctuate up and down 200 with steady pedal. I’m over the “warranty” and have been told numerous possibilities as to the cause. It sounds like a chatter, with vibration, and after reading some of the forums I have been driving in M5 without the noise. Can I continue driving it like that? Is it ok to do at interstate speeds? I love the truck otherwise but now wish I had kept my Toyota.

High Country 6.2L/8 · November 15, 2019

On 11/4/2019 at 10:55 PM, JFREED said:

I have been having a similar issue, seems to be after v4 to v8 and under 2000rpms with the greatest noise being at 1100-1300. The rpms fluctuate up and down 200 with steady pedal. I’m over the “warranty” and have been told numerous possibilities as to the cause. It sounds like a chatter, with vibration, and after reading some of the forums I have been driving in M5 without the noise. Can I continue driving it like that? Is it ok to do at interstate speeds? I love the truck otherwise but now wish I had kept my Toyota.

Did you try Amsoil ATF? I did swap a year ago through warranty which dealer paid for and no issues since. That Mobil fix is garbage that fluid doesn't hold a candle to Amsoil and the proof is in the pudding with my truck

JFREED · November 16, 2019

No I haven’t. I am thinking it’s the AFM system.

High Country 6.2L/8 · November 16, 2019

8 hours ago, JFREED said:

No I haven’t. I am thinking it’s the AFM system.

Did a AFM delete with Range and the clunking seems to have left for the most part. Dealer is going to do a relearn only a bandaid fix in my opinion. GM needs a software update

TXGREEK · November 16, 2019

Did you try Amsoil ATF? I did swap a year ago through warranty which dealer paid for and no issues since. That Mobil fix is garbage that fluid doesn't hold a candle to Amsoil and the proof is in the pudding with my truck

You’re absolutely correct, it’s made a big difference for me as well.

Sent from Above

Marshall_13 · November 30, 2020

On 5/10/2017 at 11:03 AM, 2015MDNT said:

I have the same issue, and mine started at 44K miles. I noticed it first when I have the transmission in drive and the truck is stopped, like at a light. If I shift to neutral the shudder or vibration goes away. I just got back from a 4K road trip, and I noticed at cruise of 80mph that in V4 mode the shudder was there. As soon as V8 kicked in, the shudder or vibration could not be felt. I believe that the extra 4 firing cylinders are masking the vibration. I am at the dealership right now expecting to pay $118 for a diagnostic that says they found nothing.

One caveat is I hit some heavy bumps on a short off-road experience. I noticed the vibration after that event. It may not be related, but think it's worth noting.

Hello, was the dealer able to resolve this issue? I’m having the same issue on my 2018 5.3 at around 80 mph. Thanks!

steveos3312 · December 18, 2020

On 11/5/2019 at 2:55 AM, JFREED said:

I have been having a similar issue, seems to be after v4 to v8 and under 2000rpms with the greatest noise being at 1100-1300. The rpms fluctuate up and down 200 with steady pedal. I’m over the “warranty” and have been told numerous possibilities as to the cause. It sounds like a chatter, with vibration, and after reading some of the forums I have been driving in M5 without the noise. Can I continue driving it like that? Is it ok to do at interstate speeds? I love the truck otherwise but now wish I had kept my Toyota.

Are you still having these issues? Did you find a solution or explanation? Still riding interstate in M5?

JFREED · December 18, 2020

It wound up being my torque converter was going out I got my transmission rebuilt no more issues. Also I was having an issue with my mileage and weird shifting that I thought was related to the tranny, turns out that was the MAF sensor needing to be cleaned. That was easy to do just buy the cleaner made for it.

flyingfool · December 18, 2020

if its the TCC in the converter causing the vibe, i suggest having a tuner ad more line pressure to the clutch, and correct input/output rpm slip table, then only engage the tcc at 5-6th gears, stock tune has the tcc locking in all gears, this is wearing out the tcc clutch

dont forget to do a Fast Trans re-learn after its set up..

Edited December 18, 2020 by flyingfool

Darthmalo · March 29, 2021

Hello Any solution to this issue? My truck have this vibration noise from V4 mode to V8. Going to the dealer this week for service and check this.

Edited March 29, 2021 by Darthmalo

R3SS0X · August 12, 2021

On 3/29/2021 at 10:30 AM, Darthmalo said:

Hello Any solution to this issue? My truck have this vibration noise from V4 mode to V8. Going to the dealer this week for service and check this.

Any luck? Mind started this today.