2026 GMC Sierra 1500 fuel system problems

Filed Oct 6, 2026 · Engine, Fuel system · LA

While driving on a public road, the 6.2L L87 V8 stalled without warning. There was heavy smoke and an oil trail of about 300 yards behind the truck. The engine would not restart, and the transmission would not shift into neutral. The truck was moved a short distance off the road and towed the next day to the selling GMC dealer. Odometer was 4,663 miles. Oil life remaining was 38 percent. The truck was stock, with no modifications, and was operated on premium fuel. No warning lamp was noticed before the stall. The failed engine is at the dealer and currently under inspection. The dealer inspection is not finished, and no written cause has been provided. This is a sudden loss of propulsion. Please associate this report with Engineering Analysis EA26005 concerning connecting-rod and crankshaft failures in the GM 6.2L L87 engine.

Filed Sep 28, 2026 · Engine, Fuel system · VA

Truck was sold to me and the dealership said the truck did not have the defect and the oil was changed to a thicker oil as a precaution. 4,000 miles later the engine failed, was diagnosed as catastrophic engine failure due to the known recall, and was replaced, new engine is now making the same rod knocking noise.

Filed Sep 23, 2026 · Fuel system · VA

Fuel Filter and High pressure Rail System The truck started shuddering and began to go into limp mode also shifted into neutral byitself No It was inspected by the dealership shop and now insurance Check engine light came on and code P1089

Filed Sep 9, 2026 · Fuel system · 700 miles · MO

The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving at various speeds, the vehicle hesitated to maintain automotive power and was a potential safety risk for his wife and children. The message "Shift to Park and Restart Vehicle” was displayed. The vehicle was shifted into park(P) and back into drive(D) as a temporary fix. The vehicle was taken to a local dealer on several occasions to be diagnosed; however, the cause of the failure was unknown. The failure mileage was approximately 700.

Filed Aug 25, 2026 · Engine, Fuel system · ID

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.

Filed Aug 25, 2026 · Engine, Fuel system · ID

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)

Filed Aug 21, 2026 · Engine, Fuel system · CT

I bought a new GMC Sierra 1500 Denali with the 6.2L V8 engine in December of 2025. 7 months later, I was driving home from work. When the car started, it sounded a little louder, but not out of the ordinary. I started driving and got a strange rattle when I was getting on the highway at around 65MPH. I pulled off at the next exit and checked my fluids, checked under the car to see if anything was caught that was causing the rattle. All pressures and fluids were normal. I had Onstar run a system diagnostic. The diagnostic read normal. I got back on the highway and drove about 20 miles at 75mph. The rattling continued. 20 miles later, the check engine light came on. I had onstar run a diagnostic and came back stating “engine and transmission system problem” with two error codes. One code said “An issue has been detected in the Variable Valve Timing System adjust the timing of fuel delivery for more efficient engine operation”. The other code said “An issue has been detected in the Ignition System which oversees the timing and spark necessary to ignite fuel in your engine” Both error codes said to fix within one day. The GMC dealership was on the way home so I was going to stop there and see what they could do. I never made it to the dealer. About 2 minutes after the diagnostic, while doing 75mph on the highway, I hit the accelerator and the car did not speed up. The engine then shut off while I was in the left lane doing 75 mph. The electronics stayed on and the dash stated “press start to start engine.” I pulled over to the side of the highway and put the car in park and attempted to restart the engine. The engine never turned over again. I could not get the engine to start. I could not shift the car to neutral to have it rolled up on to the tow truck. My truck was towed to the GMC dealership and they are now replacing the engine under warranty. Will upload any maintenance paperwork once engine is replaced.

Filed Aug 4, 2026 · Electrical, Engine · MI

I was driving on 96 W. in slow traffic on the freeway when the vehicle put itself in neutral and shut off

Filed Feb 23, 2026 · Engine, Fuel system · NJ

"Vehicle is experiencing symptoms consistent with the 6.2L L87 engine bearing failure investigation (the federal safety agency Probe January 2026). Despite two repair attempts, the dealer claims 'operating as designed.' I have experienced persistent engine stumble,hesitation, erratic tachometer needle flutter and significant vibrations felt through the floorboard and seats during operation. These defects substantially impair the use ,value and safety of my vehicle.This is a serious safety concern as it creates a risk of catastrophic engine seizure at highway speeds. Manufacturer has been sent a formal 'Last Chance' letter under NJ Lemon Law." Reference # 1771884

Filed Jan 21, 2026 · Engine, Fuel system · AL

2026 GMC Sierra Elevation X31 with 3.0 Duramax Diesel engine, 132-miles, thrust bearing 1.53-mm out of tolerance requiring engine and turbo replacement. Engine build date 25219 (07 AUG 2025), vehicle assembly date August 2025, purchased 10 OCT 2025, entered service for engine and turbo failure on 11 NOV 2025, returned 10 JAN 2026.