2024 GMC Sierra 1500

Lifters and camshaft failure, loud clanking, & sudden power loss on the 6.2 motor are the first noticeable signs. Instantly when everything happened check engine light, cruise control, & stabilizer lights flashed. The sudden loss of power forced the vehicle to suddenly slow down forcing my camper into the truck. I was hauling a within weight standerd camper but had difficulty bringing both the truck with the camper to a safe stop. There were no early signs or signal prior to sudden cautostrophic engine failure & all service records have been completed by a GM certified service dealer.

I was driving north/east on [XXX] just outside of [XXX]. After accelerating to give another driver room to move out of his lane that was ending, I lost propulsion/power. The Sierra went into Neutral and told me something like "Press Start to resume". I had to immediately get off the interstate as I was rapidly losing speed. I was able to pull over to the shoulder of the interstate on the right, just before exit 2. After getting the vehicle parked, I was never able to restart the vehicle. The motor would not turn over. The display screens kept cycling between a blank display and a display that looked like the vehicle was on but the engine never turned on. When I tried to start the car, I got a message of "conditions not correct for shift". We could not even get the vehicle into Neutral. I used OnStar to get State Patrol to show up and put lights behind us for safety. OnStar should have a recording of this call. This was on Saturday XXX in the ballpark of 2:30 pm central time. I would imagine the officer also filed a report, but I did not get it. The vehicle was towed to Billion GMC in Iowa City. Billion GMC said their initial suspicion is the 6.2L motor failed / locked up on us as this is know issue that is subject of a class action lawsuit. These vehicles ARE NOT SAFE to be on the highway, someone is going to get seriously injured, please do everything you can to get these 6.2L engines off the road before someone dies. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

transmission shift hard and slipping. When step on gas to go faster transmission shifts really hard like going drop on ground. Sometimes wont shift at all only goes up to 69 till left off gas and then transmission will shift. Start happening with about 10000 miles on truck and GMC said this is normal. Now need a torque converter and shift module in it.

Was traveling home and started losing power going up a hill on XXX. The truck was surging, the check engine light came on and an audible warning of no (low?) oil pressure. The truck shut off on a busy interstate highway and barely got onto the shoulder. The tow truck driver had to lay on the ground with part of his body in the lane of travel to place "skids" under the rear tires because there is no way to place this vehicle in neutral for a tow without a special GM tool. When I contacted Harry Robinson GMC service center in [XXX], they told me that it was no longer a safety recall because the truck had passed diagnostics and new, high viscosity oil was put in the truck XXX. The GMC app says code P0016 which is the dreaded 6.2L camshaft to crankshaft alignment that accompanies engine component failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Ever since I bought this truck new, I noticed a lot of metal shavings and debris in the oil filter every single time I changed the oil. I took it to the dealership multiple times to have this looked into before the engine recall came out. The dealership took pictures of the metal and sent them to a General Motors engineer, but the engineer just told them it was "normal." Later on, the truck went in for the official recall inspection, passed the PICO test, and nothing was fixed. Then on August 4, 2026, I was driving on a crowded expressway right through a construction zone with absolutely no shoulder to pull over on. Out of nowhere, the truck started hesitating badly, lost power, and the engine started making a really loud knocking noise. It was barely running, and it was incredibly dangerous because there was nowhere to go and traffic was heavy. Luckily, I was able to limp the truck along just far enough to clear the construction zone and pull over safely.

While driving on XXX I received a message on the dash: service transmission, will not be able to shift soon. I went to the nearest GMC service center, located in [XXX]. Their diagnostics indicated that the Gear Shift Control Module needed to be replaced with new PN 86421783. That part was not available until XXX, but old PN 86274946 was available at a few dealersships, and it acould possibly be ordered and arrive sooner than XXX. I was told that driving the truck would be okay, but the part should be replaced as soon as possible. I live over an hour's drive from [XXX], and with the assurance that driving the GMC was okay, I chose to have the part shipped to and replaced at the dealership in [XXX], the nearest one to [XXX]. I drove back to [XXX], stopping at the Waldoboro dealership to make an appointment for their inspection of my truck, their troubleshooting the problem, and ordering the necessary parts to repair the transmission. When the part number went into their ordering system, the dealership was advised that no parts were available and no availability date was known. I contacted GMC Customer Assistance to express my concern and request assistance in locating the parts, but she was also unable to locate the parts or speed their availability. Again, on the assurance that the truck was okay to drive, on XXX I drove to my storage units near [XXX], and when I tried to leave and shifted into reverse the truck would not move. AAA towed me to the dealership in Waldoboro, and the replacement parts search began. Finally, on 7/28/26 I was advised that the part was at the dealership, and on XXX I picked up my repaired GMC truck. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I was driving on the highway when the vehicle started to make clinking noises. The vehicle started to lose power as I accelerated it would feel like something was pulling me in the opposite direction and the knocking noise would get louder. Ultimately, I had the vehicle towed to a dealership. This vehicle passed the L87 recall not too long ago, and the vehicle is barely used.

The vehicle suffers from a persistent transmission defect including shuttering bucking slipping torque converter failure valve body failure twice metal debris improper down shifting chirping noises and related liability and safety issues. The vehicle has undergone multiple unsuccessful repair attempts at authorise GM dealerships. These repairs include torque converter replacement valve body replacement twice solenoid replacement fluid services software updates. The transmission problems have persisted despite these efforts and the vehicle has been out of service for more than 22 business days including a breakdown driving to Florida. I have filed a claim through GM but it seems like it just keeps getting pushed further and further away this is a serious safety issue as I fear for those driving around me and myself that I may cause an accident with the bucking slipping and failure to operate properly on the road.

Issue is with the transmission as it harshly shifts into a low gear when on an incline. This causes me to lock up my breaks as it feels like the truck was rear ended by another vehicle. I’m concerned that this is going to cause an accident. This problem has not been reproduced by the dealer. I’ve taken it to the dealership several times. No warning lamps or messages.