2021 GMC SIERRA 1500 Complaints

Multiple injector and lifter failures. Occurred on 2 separate occasions. Taken to dealer the first time. Told injector failure and lifter failure. Less than a week later experienced multiple lifter failures. Taken to dealer again for repair. They only replaced some of the affected lifters, even though TSB from GM recommends replacement of all of them. Currently awaiting failure of additional components not replaced. There was no warning of either occurrence. Was only driving 45 mph on my way home the first time. The second occasion was on initial start up at Dr office. Opened a claim with GM on my own, as dealership was negligent or unwilling to contact GMC about these failures, even though I provided them with the appropriate TSB directly from GM.

Engine failed due to a loss of oil pressure. Rod bearing failed which cause metal to be dispersed throughout the engine causing the engine to seize from a sudden loss of oil pressure from oil pump failure. Engine was replaced in June 2024 failure happened in May 2024. While driving a system message came on DIC that stated pull over immediately to prevent engine damage and no oil pressure. I was driving uphill with cars on my right in the #2 lane. Engine shut off before I could pull over resulting in decreased braking power and a lack of steering. I almost hit 2 vehicles trying to pull over to get my family to safety on the right hand shoulder. I couldn’t pull over to the left hand shoulder as there was a guardrail in the way. When I got my vehicle pulled over the only thing that stopped my vehicle from going over the cliff was a bunch of wood chips on the right hand shoulder. From the time the warning lights came on to the time the engine shut off and seized was maybe 5 seconds. It took 31 days to replace the engine and the dealership did an inspection on the engine. There was absolutely no warning there was any problems until the lights came on. My wife and [XXX] and [XXX] were in the vehicle at the time this happened. It was so dangerous where we broke down California Highway Patrol stayed behind my vehicle with its lights on. It was also a fire hazard with the exhaust sitting on the dry bark. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I purchased this vehicle new in 2021. It is an Ultimate Denali trim level with a 6.2 engine. Within the first year, the driver's side head on the engine had a massive failure with only 7,000 miles. I started up the vehicle and was parked idling briefly when several light came on along with a rough idle and some exhaust smoke. I contacted On Star, who could not diagnose the problem. The vehicle was disabled and ended up being towed to the dealer, where it was being repaired for 10 days. The lifters, valves and push rods were replace. The mechanic admitted there was an internal GM problem with the 6.2 engine. I asked for the same repair be made on the passenger side head. The GM dealer refused, knowing of the faulty factory installed parts. The polished tailpipe tips were not replace and were stained by the black exhaust. They are still stained this day. I purchased this vehicle for my retirement to tow my RV. Now, I have been reluctant to travel because of the other head letting go on me somewhere out west, operating under a work load. I know of two other people who purchased new GM vehicles with the 6.2 engine, who experienced the same failure, with around the same mileage on their vehicles.

at 8500 miles the engine had lifter go out while I was driving down the highway cause to truck to vibrate and becoming on unsteady causing me to pull over in the middle of traffic. later at 36500 miles it had another lifter go out this time I was driving home at a slower speed but still cause me to have to pull over vert fast as the vehicle became unsteady and vibrated causing all the alarm to come on. Both times the truck was fixed under warranty nut they replaced it with the same parts that are causing the problems. Soon my truck will be off warranty and this will come out of my pocket.

L87 engine problems. I have had failed lifters, on top of transmission issues and a current oil consumption issue where I have to add two quarts of oil (sometimes more) without any indication of low oil. I took my vehicle into the local dealership and the technician asked if I had gotten any low oil indicator and I stated no. He proceeded to tell me it had little to no oil in it. Imagine this at highway speeds and sudden engine seizure.

Transmission has a hard shift when coming out of each gear. 2nd to 1st shifts hard and jolts entire vehicle a head. Feels like a slip or difficulty in shift.

my truck keeps having this same issue since [XXX], always take it to team Gillman second august 26 same reason they replaced the battery but is a manufacturing defect while i am driving stops out of sudden AND THIS IS THE THIRD TIME THEY SUPPOSED TO CALL ME I HAVENT RECEIVE NO CALL IS AT TEAM GILLMAN SAME REASON ONLY HAS 18000 MILES MY NAME IS [XXX] CELL [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at various speeds, the tailgate opened unintendedly. No warning light was illuminated. The vehicle was taken to the dealer but was not diagnosed or repaired. The dealer informed the contact that the VIN was not included in GM Campaign Number: N232426401. The manufacturer was not notified of the failure. The failure mileage was approximately 57,000.

I received a notice of a recall for a known problem with GMC transmissions. it is very well known that these transmissions lock up and cause problems with braking and can cause the vehicle to slide off the road when the tires lock up. it also causes hard shifting, which I have experienced. GMC said they will not fix the transmission, they instead will add a device to monitor the transmission, so when the transmission locks up and causes an accident, it will let me know that it was the transmissions fault!!! How is this legal? they will let me know that their transmission caused the accident after the fact? why not fix it? typical of government to do nothing about safety... and instead make laws that allow big corporations and government to make money off of peoples deaths!

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at various speeds and downshifting, the rear wheels locked up with the parking brake warning light flashed on the instrument panel. The vehicle would resume normal operation soon after the failure. The vehicle was taken to a dealer where the contact was informed that there was a pending NHTSA Campaign Number: 24V797000 (Power Train) on the vehicle for the failure. The contact was informed that there was a temporary fix on the vehicle to repair the defect. After the temporary fix was performed, the contact experienced the failure twice within a week. The contact received a call that the permanent fix was available; however, soon after the repair was performed, the failure immediately occurred upon leaving the dealer. The manufacturer was notified of the failure, and the contact was informed that he would receive a callback. The vehicle was not repaired. The failure mileage was approximately 75,000.