2017 5.3L/8 speed lugging at throttle tip in

SGS_Z71 · February 7, 2018

So on mine today, if I brake torque it while driving down the road it will chuggle all the time. This is the first time I’ve been able to recreate it like that. Any thoughts? That tells me a torque converter problem..

I spoke with the service manager today and the truck is going back in when I get home from Tennessee. They are going to open a case with GM.

sonerick · February 7, 2018

20 hours ago, FourThor said:

Is the consensus really that this is software? Anyone here able to tune this issue out of their truck? Rather than take my 18 into the dealer yet again to be told that this issue is common and GM is waiting to make a statement I'd rather just get it fixed myself if a tune works.

This thread has the answer you are looking for:

SGS_Z71 · February 12, 2018

Well, here we go again. Dropped the truck off at the dealer this morning. I’m going to bet they throw a torque converter at it.

SGS_Z71 · February 16, 2018

Update - got an email from the service manager after 5 days that they haven’t been able to duplicate yet, and based on the data sent to GM that everything was in spec and no repairs should be attempted. They wanted me to come in to drive. I went up and took the trans tech for a ride and it did it within the first two minutes, and kept doing it. We swapped seats and it did it for him, just the same. I could tell he was embarrassed, so I let the inconvenience slide. I also told him that I haven’t filed a complaint with GM yet as I know it dings them, he appreciated that.

So... more waiting, but off the record he said I think you’re right, it’s a torque converter.

Service manager is getting annoyed with me and my documenting conversations back on email, so I must be doing something right.

Stay tuned!

SGS_Z71 · February 17, 2018

Update #2 for today:

The service manager contacted me and said he went for a ride with the tech and he asked him to check the fuel injectors as it reminded him of when one went bad in his truck. They ran a balance test and didn’t like what they saw so they ordered all new injectors. See attached balance table.

No codes/CEL, etc.

I will report back on this once I have the truck back or more info. Hopefully this is a smoking gun and can help others.

Tahoe02 · February 18, 2018

If that doesn't work I think I would insist on the torque converter replacement. Standing by to read your next up date.

SGS_Z71 · February 18, 2018

9 hours ago, Tahoe02 said:

If that doesn't work I think I would insist on the torque converter replacement. Standing by to read your next up date.

Agree 100%.

It makes sense. This same tech in November told me to try to tanks of premium to see if it made a difference. He might have been onto something then.

AaronIROCZ · February 18, 2018

On ‎2‎/‎6‎/‎2018 at 4:24 PM, FourThor said:

Is the consensus really that this is software? Anyone here able to tune this issue out of their truck? Rather than take my 18 into the dealer yet again to be told that this issue is common and GM is waiting to make a statement I'd rather just get it fixed myself if a tune works.

In my case yes it is definitely software. My 2016 6.2 8-speed had harsh shifting, for example when you slow down for the person in front of you to turn off the road onto a side street and you slow to about 10-15 mph and accelerate once they make the turn you get a rather bad harsh shift that resembles being lightly rear ended. I took it to the dealer in Feb of 2017 and they updated the transmission software along with the engine software, this helped with the harsh shifting. However I now feel the chugging and hesitation with throttle tip in at a stop sign or stop light almost all of the time now. It NEVER did this at all prior to the software update. It is going in tomorrow for this issue as well as the truck at times does not move in reverse at first start up at times, it acts like it is in neutral I rev it up and nothing, other times it bangs into gear that results in me squealing the tires while backing out of my garage. SO I will update if I get anything different done to my truck or if they fix it, which from your responses I highly doubt anything will help.

SGS_Z71 · February 18, 2018

For what it’s worth, I have had the delayed engagement in reverse and also delayed acceleration at times. Pulling out into traffic sometimes can be interesting. I hoped to tune that crap out someday. For now, I need to figure out my hestitation/chugging issue.

BamCam · February 19, 2018

On 2/16/2018 at 9:33 PM, SGS_Z71 said:

Update #2 for today:

The service manager contacted me and said he went for a ride with the tech and he asked him to check the fuel injectors as it reminded him of when one went bad in his truck. They ran a balance test and didn’t like what they saw so they ordered all new injectors. See attached balance table.

No codes/CEL, etc.

I will report back on this once I have the truck back or more info. Hopefully this is a smoking gun and can help others.

Your story is sounding more and more like my brother's and you are going down the same rabbit hole. They too were suspecting injectors and were going to replace all but later called and said they were not. Did GM put a stop to that for some reason?...not going to cover under warranty?...we don't know. At that point is when GM field guys pull data from truck and left never to be heard from again and to date still no direction to dealer for ""fix". That is why lemon law was initiated. I hope you have better luck and wish you the best.

Edited February 19, 2018 by BamCam

SGS_Z71 · February 19, 2018

9 minutes ago, BamCam said:

Your story is sounding more and more like my brother's and you are going down the same rabbit hole. They too were suspecting injectors and were going to replace all but later called and said they were not. Did GM put a stop to that for some reason?...not going to cover under warranty?...we don't know. At that point is when GM field guys pull data from truck and left never to be heard from again and to date still no direction to dealer for ""fix". That is why lemon law was initiated. I hope you have better luck and wish you the best.

We shall find out. That was what transpired late on Friday. I sure hope mine doesn’t head the same way as your brother’s. I honestly don’t want to get rid of it, but I won’t accept performance as is. I’d be ok if I got all my money back I guess.

SGS_Z71 · February 22, 2018

Update:

Got it back today and it seems to be a lot better, if not fixed. I still feel an occasional shudder, but I did in the last two loaners I had. I will be making a 1000 mile trip next week, which will be the real test. Here is the data from my work order:

February 23, 2018

3 hours ago, SGS_Z71 said:

Update:

Got it back today and it seems to be a lot better, if not fixed. I still feel an occasional shudder, but I did in the last two loaners I had. I will be making a 1000 mile trip next week, which will be the real test. Here is the data from my work order:

I hope this takes care of it. Keep us in the loop. I will use this to go back to the dealer if it corrects it.

SGS_Z71 · February 23, 2018

9 minutes ago, 13891 said:

I hope this takes care of it. Keep us in the loop. I will use this to go back to the dealer if it corrects it.

Me too. It was the smoothest drive I’ve had in a long time, I can say that. I just have doubts that they fixed the root cause versus just a symptom of it. I find it hard to believe I had that many bad injectors. Also, don’t know if anyone noticed, but the low/high pressure drops are tied to each side of the engine 1-3-5-7 and 2-4-6-8.... curious right?

February 23, 2018

1 hour ago, SGS_Z71 said:

Me too. It was the smoothest drive I’ve had in a long time, I can say that. I just have doubts that they fixed the root cause versus just a symptom of it. I find it hard to believe I had that many bad injectors. Also, don’t know if anyone noticed, but the low/high pressure drops are tied to each side of the engine 1-3-5-7 and 2-4-6-8.... curious right?

That is interesting. I wonder what spec or allowable is? Unfortunately in this time of “value improved” components it would not surprise me if there is a bad batch of injectors floating around and they have either not identified them or enough people have not made enough noise.