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Mike, Mine is fine while just revving engine at 1800. Only while driving under load which is why they didnt think it was engine related at first. At this point they are still clueless.
I guess people are not used to troubleshooting anymore
Originally Posted by MikeinAZ
would almost guarantee it's the cam sensor magnets, same symptoms I had. Luckily my dealer diagnosed it pretty quick after 2 visits. They could see the timing was off and that was a major clue as there is no cel thrown. I'm shocked at so many of these issues being misdiagnosed. Especially since if the car is put in neutral and reved, the issue is still there eliminating the trans from the equation.
With more and more of these issues popping up its surprising GM is still misdiagnosing so many of them. Makes me grateful at least mine was fixed relatively quick.
They just go by what the software says to do. It guides them down a flowchart of yes/no decisions. Now, imagine if this was not under warranty. You could be in for tens of thousands worth of repair work for something that costs basically nothing to fix.
They just go by what the software says to do. It guides them down a flowchart of yes/no decisions. Now, imagine if this was not under warranty. You could be in for tens of thousands worth of repair work for something that costs basically nothing to fix.
There really are no excuses for mediocre/poor tech analysis. Cars today are high tech and you do need troubleshooting procedures and guidelines. But, most of the people in the industry have little knowledge outside of a book or computer screen. Some things strike me as just common sense. I sometimes look at all kinds of data on problem vehicles and the first thing I do to analyze a problem is just sit in the vehicle and maybe drive it to get a sense of what is happening. I try to reproduce the problem while looking at all of the conditions associated with this. A tech needs the ability to be able to use his/her senses to see what is happening. It helps to have knowledge of internal combustion engines and the principles on which they work. It helps to have tuning experience with knowledge of what happens when things like spark, fueling and valve timing are off. A tech needs to integrate diagnostic flow charts with what his senses are telling him about the vehicle. Maybe I just have too many years doing this, but I see misdiagnosis all the time. There just is no excuse for mediocrity on complicated, high tech equipment. It is up to every individual working in this field to improve their performance, to have accomplishments they can be proud of and most of all, to be driven to end up with satisfied customers who were given an expedited and efficient repair. In the end, each individual has to ask themselves: what are they worth? I want my work and reputation to be priceless.
Mike, Mine is fine while just revving engine at 1800. Only while driving under load which is why they didnt think it was engine related at first. At this point they are still clueless.
That was around the rpm mine was most pronounced, if I had the cruise control on it would do it, it would do it accelerating as well. It would NOT do it at full throttle. I would rip off 2.9 0-60 times w/out issue but anything at part throttle would do it. When it was cold or first driven the symptom was masked a bit, I could tell it was there but not nearly as bad. As the car warmed up it became more pronounced. In hindsight obviously that was due to the timing.
My dealer first checked for a vacuum leak (that's what it feels like) and had me remove my performance parts, I had a PTR manifold and Soler tb on it. Took those off and was still doing it, they considered the trans but then called me and said the timing was showing off in their tests and GM said to replace the cam sensor. So not sure why that same diagnosis isn't more popular as GM has to be involved.
Just had my transmission replaced and the car still bucks under light acceleration between 1800-2200 rpm, most noticeably on the highway in manual mode
What have they done now that it was not the transmission??
I agree with what undecided1965 says, I fix CNC’s for a living and we do have processes that we go by to fix these Million dollar machines but after just a few and not getting anywhere we go off on our own troubleshooting to find the issue and get it resolved. We then write up our own TSB and place it on the server for the next guy. I’ve been doing it this way for 23yrs and there’s not a machine yet I haven’t fixed..
The processes must be very different in this Industry than mine.
I had the Idle Creep Disable Message..... Took it to the dealer today (Car is 3 weeks old 425 miles)... Rep says I need a New Valve Body (O and its back ordered).... WTF!!!!!!!!!!!!!!!!!!!!! The car drove fine, Engine light was on them it went off... But I took it to the dealer just to clear out the code.. and do any updates... Tech said not enough oil pressure was going through....(So was it low at the factory.... SMDH) . I hope this fix the problem.
Just to RECAP. My issues started from Delivery. SHUDDERS hard at 1800 RPM in any mode any gear. Only while driving with a LOAD. Meaning you have to be going up a slight incline. Not down hill. Does not shudder if just running engine at 1800 sitting still..1st week at dealership to flash the TCM and update . Did nothing... 2nd trip to dealership They decide to replace the transmission as apparently can not open it at all.to fix. 2.5 weeks later and $21K , paid by warranty, Still had same issue.3rd trip to Dealership replacing the transmission did nothing so now GM tells them to replace the Valve Body.... Im like but wait.. You sd you couldn't do anything on the transmission now they want you to replace the Valve body which is in the transmission. Plus WTH would that be the issue unless you are saying that was also the issue in the first transmission but you replaced the whole thing instead of just trying the valve body first...before tearing the whole car apart to replace the whole transmission! Next question.. When this doesnt fix the issue what are you going to do??? Replace the Engine! At this point it is at 29 days...Lemon law here we come! What a
sapain
Thank you so much for sharing this and hope it does help someone going to forward t else out having similar problem. Your last statement was so funny but true. I guess it’s worth it now having a car that runs sooo much better. Seems like it was dirty in there during the building of engine.
Did you ever get this resolved and if so what was the issue? I have just over 8k miles and car has been flawless and I've modded it slightly. 2M cats, Atak blue filter, Lingenfelter intake manifold and throttle body....the car has run perfect! About a month ago it started stumbling and hesitating when driving and accelerating, but only after a few miles of driving and all fluids getting to up over 170 degrees. Runs fine prior to that and idles fine. Strange thing its run fine w/ all these mods for close to a year, just started doing this out of nowhere, almost feels like a vacuum leak but it wont do it for a few miles after starting, everything has to be warmed up but no cel coming on.
Taking it in monday to have dealer run some tests/scans, almost seems its some sort of sensor since it doesn't do it till its fully warmed up. Curious if anyone has any ideas and if OP found a resolution.
It seems all of the motors from 2020 through 2025 have a timing problem caused by a sticking camshaft actuator. It's a $30 part that mounts on the motor and helps control the camshaft timing but in order to replace it the motor has to be dropped. It's about a $12,000 repair. It seems they start sticking over time. Mine had a problem that slowly developed over a year ans thankfully a good service technician found the attached. They ran one quick test on mine and saw that the actuator was completely out of timing.
This is a 2022 technical service bulletin but it has an update as of September 2025 that includes all 6.2 Motors through 2025. This includes Corvettes and even some SUVs and trucks!
It seems all of the motors from 2020 through 2025 have a timing problem caused by a sticking camshaft actuator. It's a $30 part that mounts on the motor and helps control the camshaft timing but in order to replace it the motor has to be dropped. It's about a $12,000 repair. It seems they start sticking over time. Mine had a problem that slowly developed over a year ans thankfully a good service technician found the attached. They ran one quick test on mine and saw that the actuator was completely out of timing.
This is a 2022 technical service bulletin but it has an update as of September 2025 that includes all 6.2 Motors through 2025. This includes Corvettes and even some SUVs and trucks!
GoodLuck!
I was on this thread when it started years ago, first known problem GM had found from the sounds of it, was a pain then as there was no data on it but they did find the issue relatively quickly. Crazy to me all these years later some dealers don't know the issue exists and there is a tsb on it and yet they throw all sorts of solutions at it and it doesn't fix it. My timing was way off, once they ran that test they figured it out pretty fast. I've moved on and sold that car and have a Z06 now but this thread pops up from time to time and it stinks reading that GM hasn't found a fix (no surprise there) and so many people are not getting the proper diagnosis.
It seems all of the motors from 2020 through 2025 have a timing problem caused by a sticking camshaft actuator. It's a $30 part that mounts on the motor and helps control the camshaft timing but in order to replace it the motor has to be dropped. It's about a $12,000 repair. It seems they start sticking over time. Mine had a problem that slowly developed over a year ans thankfully a good service technician found the attached. They ran one quick test on mine and saw that the actuator was completely out of timing.
This is a 2022 technical service bulletin but it has an update as of September 2025 that includes all 6.2 Motors through 2025. This includes Corvettes and even some SUVs and trucks!
GoodLuck!
Why does the TSB still only show 2022s? Also, is the fix permanent? And, why have they not improved the repair procedure to not require an engine drop? $12K? That's 60 hours at my dealer's hourly rate.
like @MikeinAZ said unbelievable that this is still going on. I posted that same TSB nearly 3 years ago now when my car was having issues. My car was at the dealer for a week and they had to drop the engine/subframe assembly to change a $50 part. Surely they could have come up with an upgraded component by now.
Why does the TSB still only show 2022s? Also, is the fix permanent? And, why have they not improved the repair procedure to not require an engine drop? $12K? That's 60 hours at my dealer's hourly rate.
Per Page 1, Vetts 2014 - 2022 BUT in Sept 2025 GM issued an update to include Vetts thru 2025.
The bumper has to come off, the exhaust, then the motor has to be dropped. Part is only $30 but all labor based cost. Mine was replaced. So far, no issues but we will see if the problem returns. Took three days as they have to disassemble, repair, reassemble, re-tune the vehicle after reassemble, then drive, it, let it set for a day, recalibrate, and drive again.
Own a Vett? BUY AN EXTENDED WARRANTY if you want to keep it past 3/36!
Mine was CPO so all of mine was covered under warranty.
Wouldn't this be covered by the 5 year powertrain?
Originally Posted by TEvans
Per Page 1, Vetts 2014 - 2022 BUT in Sept 2025 GM issued an update to include Vetts thru 2025.
The bumper has to come off, the exhaust, then the motor has to be dropped. Part is only $30 but all labor based cost. Mine was replaced. So far, no issues but we will see if the problem returns. Took three days as they have to disassemble, repair, reassemble, re-tune the vehicle after reassemble, then drive, it, let it set for a day, recalibrate, and drive again.
Own a Vett? BUY AN EXTENDED WARRANTY if you want to keep it past 3/36!
Mine was CPO so all of mine was covered under warranty.
But, I did buy an extended warranty based on these types of problems.
. Taking in car again today. I have tried transmission fix, that resulted in new fly wheel. Tried cam adjustment 2,3 to 1degree. All fantastic suggestions that were necessary! But hadn’t fixed the problem. Today guy from Chevy is looking at it. Found a thread about 6.2 l. Engines being bad. We’ll see how that goes. Have contacted easy lemon and we’ll see how that goes. It’s my last choice, but it’s becoming ridiculous. Car has been out of se tree Vice basically since Jan 20.
. Taking in car again today. I have tried transmission fix, that resulted in new fly wheel. Tried cam adjustment 2,3 to 1degree. All fantastic suggestions that were necessary! But hadn’t fixed the problem. Today guy from Chevy is looking at it. Found a thread about 6.2 l. Engines being bad. We’ll see how that goes. Have contacted easy lemon and we’ll see how that goes. It’s my last choice, but it’s becoming ridiculous. Car has been out of se tree Vice basically since Jan 20.
I remember a guy who was messaging me when I had my issues and his were similar, ended up being a bad plug or two. Maybe they can check the plugs for a misfire. Good luck.
I guess people are not used to troubleshooting anymore
The car drove fine, Engine light was on them it went off... But I took it to the dealer just to clear out the code.. and do any updates... Tech said not enough oil pressure was going through....(So was it low at the factory.... SMDH) . I hope this fix the problem.
