Been a proud and hardcore Powerstroke fan/owner since they first came out. last one was at 193k miles so I decided it's time for a new work horse. Wanted another Powerstroke, but I couldn't get one at a lower price or with a better warranty then what Chevy was offering me on a 2020 Chevy LT 2500HD Duramax/Alison package. Figure they are a good American company so I went ahead and bought it. Turns out the warranty is so good, because you are more likely to need it.
Bought the truck at the start of November 2020 and have 4,100 miles on it now with no towing yet. Majority of the miles were highway driving to different hunting locations last month here in Montana. Started heading to work this morning and about 4 miles from my house the truck started surging RPMs and shifting hard between lower and higher gears. Managed to nurse it another mile or so to a safe place to pull off the road. Once stopped with my foot on the brake and the vehicle in drive, the truck was still shifting and trying to jump forward against the brakes (still no lights, codes, or messages). Put it in park, tried switching between D and L gears to see if maybe the ECM or TCM was just getting so smart that it was confused. Nothing different though. Put it back in park, shut it off, let it sit off for about 10 minutes to hope something would reset itself. Started it back up (still no lights, codes, or messages), same issues: high idle, surging RPMs, and shifting/attempting to drive against the brakes when in Drive.
Called the dealership, they asked me a bunch of questions, sounded like they didn't believe my issue was real (still no codes, messages, or lights). They had me call through OnStar for a tow. After getting off the phone with OnStar I tried shutting it off and turning it back on again. Only change at this point was that now all my warning lights were on, dash messages were that parking brake, ecs, and tcs need serviced.
Tow truck showed up and while running (wouldn't let me put in neutral while off), in neutral, and going onto the truck the transmission was making an unhealthy sound similar to when a starter doesn't hit the flywheel right. Put it in park and shut it off for the trip to the dealership. Got to the dealership, started it back up and put it in neutral for unloading. Only light on now is check engine light and a service parking break message. Transmission still didn't sound healthy.
Went into the service department and they sounded sceptical that I had an issue, but said "they might get to it today, but we're pretty booked up". Didn't offer me a loaner vehicle. So, really pleased that I have a $58k dealership parking lot weight currently. I don't expect that every single thing made will work without issue or that I should be treated like a king, but I do expect to be taken seriously when reporting an issue, at least asked if I have another mode of transportation, and given at least some educated guess at the problem and when to possibly expect a remedy so I can plan future transportation needs accordingly.
$58k was a lot of money that I thought would buy me reliability and piece of mind. I haven't lost piece of mind with the vehicle itself, but rather the lack of customer service and care that I can expect in the future. After you've spent the money you quickly become a nobody with GM apparently.
Will continue to update if I get any information regarding the cause of this issue and a solution.