AFM vibration in V4 mode

SOL24/7 · October 3, 2016

I recently purchased a new 2016 Silverado 1500 with the 5.3 a couple of months ago. Everything was going fine until a couple of weeks ago when I started getting a vibration when it goes in to V4 mode. Im wondering how many others are having this problem and if anyone knows if Chevrolet has a fix for it.

Thomcat · October 4, 2016

.02

AFM problems in earlier engines resulted in oil ring clogging and oil fouling of plugs usually presenting after 50K miles and effects noted in both V4 and V8 modes. Engine modifications subsequent to 1/2011 addressed all of the previous AFM 5.3l related design defects.

Shouldn't be any vibration problem directly caused by AFM in later engines; vibrations that exist in some Silverados appear to be more of a harmonic problem related to specific engine speeds. A vibration problem when operating only in V4 could be related to a spark or compression imbalance in one of the 4 remaining powered cylinders which becomes more noticeable once the other 4 AFM cylinders are deactivated.

tuckersnator · October 4, 2016

Get the Range AFM disabler. I, (and almost everyone else here) has the V4 shudder. I love the full time V8 now. You could also do a tune but that may void the warranty.

Thomcat · October 5, 2016

Get the Range AFM disabler. I, (and almost everyone else here) has the V4 shudder. I love the full time V8 now. You could also do a tune but that may void the warranty.

Had the 5.4 V4/8 in my '07, '12 and '13 Avalanches as well as the '16 Silverado and never got what I would call a vibration from any of them. Used the Range Technology disabler on the unmodified '07 and it sits in my toolbox, never felt a need to use it on post 1/2011 engines which contain the cumulative AFM corrective mods.

OP indicates engine worked fine as a V4/8 for a few months and then developed a vibration in V4.....AFM transition or operation in V4 does not cause a constant vibration, perhaps a slight bump during transition and noticeable change in exhaust pitch riding with the window open, but the engine does this from day one of operation not as the OP described as suddenly appearing after a few months operation. Any sudden change appearing in engine operation should be subject for concern. A proper diagnosis is in order to determine if the problem is in fact a weak AFM cylinder or other imbalance noticeable in V4........the solution should not be to mask it by using the Range Technology disabler until something finally blows once out of warranty.

AllTerrainX · October 8, 2016

I had an 07 Avalanache, bought a Range AFM disabler for that. I now have a 16 Sierra SLT All Terrain and I have noticed when in V4 mode at slow speeds cruising (less then 40mph), slowing and speeding up with traffic, if I give it some gas it seems to bog a little and it kinda feels like it vibrates a little. But once it hit V8 mode, it goes back to normal. Never been a fan of AFM.

If I install the Range AFM disabler into my brand new 16 Sierra, will that void my factory warranty?

Edited October 8, 2016 by AllTerrainX

AllTerrainX · October 11, 2016

So I have been testing for a couple days. When cruising 35-45mph zones, if I am in regular Drive, I hit V4 mode all the time. But with Manual shifting, it never goes into V4 mode, ONLY when I shift it into 8th gear. Downshifting into 7th or lower, it never engages V4. Going to keep testing this out for another week.

Edited October 11, 2016 by AllTerrainX

ShamrockShooter · October 11, 2016

Mine makes a chirp from the flapper valve after the muffler everytime it goes from v4 to v8. It is especially noticeable with the rear slider open

Billy346 · October 11, 2016

Had the 5.4 V4/8 in my '07, '12 and '13 Avalanches as well as the '16 Silverado and never got what I would call a vibration from any of them. Used the Range Technology disabler on the unmodified '07 and it sits in my toolbox, never felt a need to use it on post 1/2011 engines which contain the cumulative AFM corrective mods.

OP indicates engine worked fine as a V4/8 for a few months and then developed a vibration in V4.....AFM transition or operation in V4 does not cause a constant vibration, perhaps a slight bump during transition and noticeable change in exhaust pitch riding with the window open, but the engine does this from day one of operation not as the OP described as suddenly appearing after a few months operation. Any sudden change appearing in engine operation should be subject for concern. A proper diagnosis is in order to determine if the problem is in fact a weak AFM cylinder or other imbalance noticeable in V4........the solution should not be to mask it by using the Range Technology disabler until something finally blows once out of warranty.

I really like this response. If I can add to it, depending on the speeds you drive, and if the AFM bugs you to a certain degree, you can just keep the truck in M5 while driving around town and on the highway below 60 MPH. When in M mode, the engine doesn't go into V-4 unless you select M6. I have dual exhaust on my truck, so I'm not crazy about the tone change of the engine when it goes into V-4, so I leave it in M4 or M5 when I'm driving around town. When I'm on the highway, I put it into M6, where I don't really feel any transition, and the change in exhaust note is muffled by tire whine and wind noise.

I thought about buying a Range AFM delete, but decided against it because driving it in M5 completely eliminates what bugs me for most of the time I spend in the truck. Additionally, while the Range doesn't leave an imprint on your computer, it can cause trouble for you if you live in a state that has strict emissions compliance laws (which I do).

silveradosid · October 11, 2016

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

2015MDNT · May 10, 2017

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

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.

silveradosid · February 25, 2018

i now have 110 kilometers or 70 k miles on my truck and the vibration at 70 k or 45 mph is so bad that i have to drive my truck in manual mode. when the truck shifts from v8 to v4 the rpms jump almost 200 rpms and does the same when it shifts back to v8. is this normal for the rpms to be jumping up and down like this also in v4 mode the rpms fluctuate about 50 rpm all the time

Edited February 25, 2018 by silveradosid

dspar00a · January 16, 2019

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.

Sierra Dan · January 16, 2019

Most of what I have heard is that the vibrations are felt in the floorboard and steering wheel starting at 1500 RPMs and Ranging up to about 1800 RPMS whether in V4 or V8

dspar00a · January 16, 2019

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.

AtlasFBG2 · January 16, 2019

4 hours ago, 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.

Get a Range device so it wont go into v4 mode.