2017 GMC Sierra 1500: Surge, Hesitation, Chuggle, Misfire, Feeling wit

[kevinfranklin]

1 hour ago, Bushleaguechew said:

Not to discredit anyone’s problem or suffering but is this not a symptom of every modern automatic transmission? They are all programmed for fuel economy in mind and to hunt for top gear. In stop and go city driving/traffic my truck will behave like a total pig if I mash the gas and brake like a chump. But if I drive with any amount of finesse it behaves fine.


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No, it sounds like your vehicle just happens to not exhibit the issues a few of the others do.  Mine "hunts" and struggles when finessing it around town, more so than the other 14+ vehicles my wife and I have owned in he past. 

[Brian-Spokane]

The point isn't what GM is trying to achieve.  The point is very few drivers expect the vehicle too nose dive when they push on the gas pedal.  The simple act of pushing on the pedal is not fuel efficient.  I believe the manufacturers should have two buttons.  NoseDive mode - programmed by GM with their hidden agendas (like the 2018 GMC Sierra). Or ...  Normal mode - the mode that meets most  clients' expectations.   In the meantime, i suggest the non-NoseDivers put the xmission in L4.  Easy Peasy.

[TRG]

Ugh - my new 2018 Silverado does the same things mentioned in this thread.  I picked up a Range to disable the AFM and that definitely helped, but still have chugging/fish bite/hesitation issues when trying to hold a constant speed.  It goes away if I punch it and force it to downshift, but if I just try to hold a consistent speed, it's a misfiring stumbling mess.  Haven't contacted the dealer yet...trying to do all the research beforehand to see if there's something specific I can recommend to them to try to help solve the problem.        

[TRG]

On 2/12/2018 at 11:05 PM, Brian-Spokane said:

My 2018 Sierra 1500 5.3L 6-speed  does this ... big time.  After 1500 miles i figured out how to eliminate the issue.  Put the xmission in "L" then shift  with the '+' and '-' buttons on the shifter until it is in L4 just for in-town driving (less than 40mph). Limiting it to 4th gear prevents it from shifting into 6th gear so it doesn't lug so much plus it wont down shift as much. Also, this mode doesn't go into V4 mode.  and the torque converter kicks in/out as expected. Give it a shot and let us know if it works for you. 

 

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Curious, why not just put it into L5 instead of L4?

['17 Sierra]

19 minutes ago, TRG said:

Curious, why not just put it into L5 instead of L4?

Correct...L5 will keep it out of AFM too.

[Brian-Spokane]

GM's programming wants to put  the transmission in the highest gear.  This causes the xmission to shift/hunt a lot around 1500 RPM. Maybe in your experience 1-5 works better.  In my humble opinion, with in town driving, the RPMs are just fine in 1-4 gears.   Less shifting, means less hesitation.   This also means immediate fuel delivery to the engine in a proportionate manner which is exactly what I would like to see them fix. 

[TRG]

10 hours ago, Brian-Spokane said:

GM's programming wants to put  the transmission in the highest gear.  This causes the xmission to shift/hunt a lot around 1500 RPM. Maybe in your experience 1-5 works better.  In my humble opinion, with in town driving, the RPMs are just fine in 1-4 gears.   Less shifting, means less hesitation.   This also means immediate fuel delivery to the engine in a proportionate manner which is exactly what I would like to see them fix. 

This is exactly what appears to be happening...even when on the highway in 6th gear and trying to keep a consistent speed.

 

Anyone out there with a 2018 5.3L 6spd that's had any luck with the dealer coming up with a solution to this mess?

[olds442]

I'm having the same problem with my 2018 Silverado, 2000 miles.    I hate to drive it, I wish I had kept my 2007 with 156,000 miles on it, $40,000 mistake.

[Brian-Spokane]

Agreed. It sucks that we get stuck with these poorly programmed vehicles with terrible driveability. It sucks even more that we have no voice in getting the issue fixed.   We already made a wrong statement by purchasing the damn thing.  I personally try to raise awareness by posting this issue on as many websites as possible.  Maybe, just maybe, these posts will influence potential buyers from making the same mistake and GM will start listening. 

[FourThor]

This is exactly what appears to be happening...even when on the highway in 6th gear and trying to keep a consistent speed.
 
Anyone out there with a 2018 5.3L 6spd that's had any luck with the dealer coming up with a solution to this mess?

I’ve taken mine to the dealer twice for this issue and the ridiculous rough idle vibrations. Both times I got a canned response about how this is mostly normal and GM hasn’t said anything. I didn’t plan on voiding my warranty anytime soon, but I’m likely going to pull the trigger and just tune out the issue when I get my lift on this spring. Seems to be the only fix.


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[miker2702]

I had a 16 2500 no afm 6.0 liter

4.10 hear.

 

Traded to 17 1500. Now I understand the hate for arm.

The shaking vibration shuttering

Etc. 

[kevinfranklin]

37 minutes ago, miker2702 said:

Traded to 17 1500. Now I understand the hate for arm.

The shaking vibration shuttering Etc. 

So do you feel the shake/shudder:

1. only when shifting at lower speeds (1st gear to 2....and maybe 2 to 3) ?

2. ONLY when the tranny shifts from 8 cylinders to 4 and back?

3. when gently cruising at lower consistent speeds

4. at higher speeds or more aggressive shifts?

 

I feel it mostly during #3.......just gently accelerating and cruising around town. 

[miker2702]

Yeah 3 ,would be best description. To bad interior

Mostly quiet ride smooth.

Engine and trans can't work well together

[olds442]

# 1 & 3

[mouse24]

I have a 17 1500 that I had them do the TSB upgrade. It mostly solved the problem.

Mine would chuggle (whatever the hell that is) when I'd be rolling down the highway and just start to put a bit of a load on the engine (as is starting up a small grade).

 

The TSB did fix that. I'm still trying to learn more about this tuning option.