GMC Sierra Reliability by YearBest & worst years, problems & recalls — NHTSA data

Took ownership of this vehicle on XXX. 6.2 motor build date XXX at Tonawanda plant. Currently have 10,600 miles on vehicle. First and second oil changes at GMC facility T&T Coast Buick, GMC located in [XXX] First at 4,441 miles, oil part number 19420077. Second oil change at 8,379 miles, oil part number 19420077 This oil part number is for 5W-30. ACDelco bulk engine oil (Dexos1 Gen2 Full Synthetic 5W-30). The correct oil was not used. From what I have read this is a GM "oil trap" so if there is a problem with the motor GM can deny warranty coverage because the wrong oil was used. I have not adressed this with the dealership yet. If there is a 6.2 motor problem with my vehicle in the future am I going to be denied coverage? I am worried. I also have the extended warranty. Thank you. [XXX] [XXX] [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

While driving through city traffic at approximately 35 mph the truck engine made a quick loud noise and then immediately shutoff. The power steering went out and then I was unable to pull off the road completely as the engine would not start back up. This truck is a 2026 with 9,000 miles, 6.2L motor. After being towed to a GM Service facility it was determined that the motor had blown up on the truck. A vehicle shutting off while driving down the road is an extreme safety concern in my opinion.

Learned that GMC engines may have an issue. We haven't had one as yet.

This truck has the GM L87 6.2L engine that is currently on recall for 2021- 2024 model years, but recently the NHTSA is looking into post engine replacement failures and 2025-26 model year issues. My engine at 7,000 miles failed for rod bearings. Same issues reported years ago and 100k engines ago. GM has not fixed the problem, its still happening.

The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving approximately 60 MPH, the transmission unexpectedly downshifted and the vehicle decelerated to 10 MPH. No warning light was illuminated. The contact pulled over to the shoulder of the road, and the vehicle was towed to a local dealer. The vehicle remained with the dealer for additional diagnostic tests and unknown recurring failure codes. In addition, the contact stated that the failure worsened and occurred while his wife, sister-in-law, niece, and child were present inside the vehicle. The vehicle was not repaired. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 7,500.

Bought the vehicle brand new at the end of april. 2 weeks later and at 557 miles, the engine had a lifter failure and needed to be replaced. One day after picking it up after the engine replacement, a fuel injector went bad and needed to be replaced. About 2 days ago, the check engine light lit up, and the GMC app said it was a code for the transmission system (popped on after attempting to remote start the vehicle, although the light did shut off on its own the next day after a software update on the vehicle)

I bought the vehicle brand new in april 2026. On May 3rd, approximately 2 weeks after I bought it, I experienced a lifter failure that caused metal to get into the oil pan/engine and the engine needed to be replaced. About a month later after repairs were complete, I picked up my vehicle on a Friday night, and the very next morning, had issues again. Took it back to the dealer and a fuel injector went bad and needed to be replaced. I recently attempted to use the remote start feature and as soon as it fired up, the engine cut out. I went to start it again and the check engine light came on. My GMC app said the code was transmission related, although it cleared on its on the next morning after a software update.

rocker arms replacement at 5,000 miles on my truck. Palm Harbor Tasca GMC

What component or system failed or malfunctioned, and is it available for inspection upon request? The truck has lost power unexpectedly while driving, and lately I've also noticed some lag when I accelerate. The truck is available to be inspected. How was your safety or the safety of others put at risk? The truck suddenly lost power while I was driving and told me to restart the vehicle. Losing power unexpectedly almost caused me to get stuck in an intersection and could have caused an accident in a busy shopping center. Has the problem been reproduced or confirmed by a dealer or independent service center? No. I took it to the GMC dealership after the second time it happened, but they couldn't get it to do it again and said there were no codes showing. They told me to bring it back if it happens a third time. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Yes. I took it to the GMC dealership to have it checked after the second power-loss issue happened. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? When it lost power, the truck prompted me to restart the vehicle. I have also recently started noticing some lag when accelerating and starting the vehicle. There was no warning before it happened.

Truck milage at the time of engine failure was 9,101. Well past the break in period for towing. We were towing a car trailer 2,000 pounds less the max towing capacity for the truck and going less than the posted speed limit. The truck was also in tow haul mode. The truck dash flashed oiled heating hot. We tried to pull over on the highway then the truck lost all power and overheated. Our trailer was not all the way off the highway, so a WY State Trooper pulled behind us and kept his lights flashing for 3 hours until a tow truck came. Truck could not be placed in neutral, so it had to be dragged onto the flat bed ramp of the tow truck. Truck was towed to the Gillette WY GMC dealership that same day. On Monday we were informed that the engine failed and needed to be totally replaced. The GM dealer cannot tell us how long it will take to get the new engine or how long we will be without the truck. This is the 6.2 V8 which GM assured buyer's of 2026 vehicles that the engine failures reported on previous year vehicles had been rectified on the new models. Less than 10,000 and the engine failed.

Engine completely failed and had to be replaced

The contact owns a 2026 GMC Sierra 1500. The contact stated that intermittently there was no sound while the turn signals were activated, and the radio and incoming calls failed to be audible. The issue often lasted all day or for an hour or two before returning to normal. The contact associated the failure GM Technical Service Bulletin: PIT6406 (or PIT6406F), but the dealer stated the vehicle was not included in the bulletin and refused further diagnostic tests. The vehicle was taken to a dealer to reprogram the Audio Control Module (ACM) because the software was outdated, despite the vehicle being brand new. The reprogramming was completed; however, the failure was not resolved. The manufacturer was notified of the issue. The failure mileage was 3,657.

This engine has used more than 2 quarts of oil since purchased in November of 2025. It has 12,000 miles on it. The exhaust pipes are covered in black soot from oil burn. It scares me to drive it, $87,000 retail vehicle worth about nothing with a bad engine. Terrible

Catastrophic failure of engine while exiting the interstate.