2026 GMC Sierra 1500 Engine Problems

2026 GMC Sierra SLT with 3.0 Duramax diesel engine. While driving down the road with the cruise set to 55 MPH on 8/29/26, the engine started to run rough. I slowed down, but this did not seem to help; I sped up, and the problem persisted no matter what I did. Service traction control and service ESC displayed on the dash. I drove to the dealership; their service department was closed because it was Saturday. I took my salesman for a ride so he could witness the issue firsthand. He confirmed something was not right, and they put me into a loaner vehicle. The truck has 848 miles on it. Service diagnosed it as a fuel issue in cylinder 2, replaced the injector, but the issue did not go away. GM TAC team advised replacing the motor; that is what I am currently waiting on. The dealer has the motor and is awaiting the install.

NHTSA ID

11766683

Incident

Aug 29, 2026

While turning right and at a slight incline the truck engine turned off, the transmission made a grinding noise, the truck went into neutral and the dash stayed “Press Start Button”. This is the second time this has happened within 5000 miles of the struck being purchased. Several others have reported the exact same issue on Facebook forums.

NHTSA ID

11766519

Incident

Sep 23, 2026

The contact owned a 2026 GMC Sierra 1500. The contact stated that while accelerating from a red light at 15 MPH, the vehicle sputtered and shook before finally moving forward. The contact stated the failure was a recurring failure. The contact associated the failure with NHTSA Action Number: EA26005 (ENGINE). The dealer was contacted. The failure mileage was approximately 160.

NHTSA ID

11765942

Incident

Sep 17, 2026

Mileage

160 mi

Engine blew on a 2026 GMC AT4X with the 6.2 motor. Has been inspected and confirmed by dealership. No warning on failure, was passing a car when power was lost and warning system said restart engine.

NHTSA ID

11765646

Incident

Aug 23, 2026

The contact owns a 2026 GMC Sierra 1500. The contact stated that while at a stop light, the engine shut off to save fuel, but after releasing the brake pedal, the engine failed to restart. The contact shifted to park, and the engine restarted. The contact stated that the failure had occurred on several occasions after the fuel saving feature was deactivated. Additionally, the contact stated that the failure had occurred while slowing down and driving over a railroad track and hauling a trailer. The vehicle was taken to the local dealer on several occasions, but the failure was not duplicated. The manufacturer was notified of the failure. The failure mileage was 4,300.

NHTSA ID

11765373

Incident

Jul 16, 2026

Mileage

4,300 mi

My 2026 GMC AT4X 6.2 liter engine had a lifter fail for #5 cylinder due to a faulty designed crankshaft bearing causing a knocking with the engine running. It required the engine to be replaced by GMC at only 7100 miles. The dealership admitted it was a defective/incorrectly manufactured part that caused the failure. I wanted to report this since GMC had said this issue had been corrected on the 2026 model year engine, but I have been reading that this issue is still occurring in the new vehicles and at a very low mileage instance. Mine failed at only a little over 7,000 miles.

NHTSA ID

11765327

Incident

Jul 27, 2026

The 6.2L L87 V8 engine in my 2026 GMC Sierra 1500 suffered a sudden, catastrophic mechanical failure and shut down completely while driving at 65 mph with only 6113 miles on the odometer. There were no dashboard warning lights prior to the seizure, resulting in a sudden and dangerous loss of power. I was towing a 30 foot camper at the time and passing an 18 wheeler, it was truly a dangerous situation at the time and my wife and I feel very fortunate that we that we didn’t have a fatal accident.The dealership confirmed a total engine failure/seizure and had to replace the entire engine assembly under warranty."

NHTSA ID

11765185

Incident

May 31, 2026

The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving 35 MPH, the vehicle stalled. Additionally, the wheels locked up, and transmission made a screeching sound. The contact was able to restart vehicle after approximately 5 minutes. The failure was recurrent. The vehicle was towed to the dealer, but the dealer was unable to duplicate the failure. The dealer replaced an unstated module that was damaged during the failure. The manufacturer was contacted by phone and was made aware of the failure. The failure mileage was approximately 6,000.

NHTSA ID

11764644

Incident

Aug 11, 2026

Mileage

6,000 mi

Catastrophic engine failure. A 2026 GMC Sierra with only 7360 miles had engine failure while driving at 45 miles per hour which resulted in no power from the engine to assist in getting the truck off the road and stopped safely out of the road. In my case, it happened late at night so traffic wasn't an issue. I was just stranded in a dark, rural area late at night. If this happens to someone in traffic, the results may be much different from mine. After this incident, I learned that this is not uncommon and many trucks/SUVs with the GM 6.2L engine have failed in the same or a similar manners and earlier models have been recalled for the same issue.

NHTSA ID

11764358

Incident

Aug 28, 2026

on Friday the 11th the vehicle quit running had to be towed and left me stranded in the middle of an intersection. This is a second vehicle from GM with the 6.2 L engine that has done this to me. The dealer says it’s catastrophic engine failure, and they’re gonna replace the engine. I was told that GM Edward repaired this issue but is still selling brand new trucks with this motor that has this failure, they can lead people stranded in very compromising positions.

NHTSA ID

11764203

Incident

Sep 11, 2026

At just below 5,000 miles of use, my new 2026 GMC Sierra At4 (6.2L V8 engine) is currently undergoing a total engine replacement arising from traces of metal being detected in the oil filter. Although covered by GMC Warranty since it is essentially a brand-new vehicle, I wanted to report this issue as it is most likely part of the large GM recall pertaining to this L87 engine since I am concerned this is related to ongoing 6.2L L87 engine failure investigation. It is expected to be out for around 4-6 weeks with a new engine incoming and would want to be covered if the new engine fails in the future with any issues relating to this case.

NHTSA ID

11764094

Incident

Sep 5, 2026

Was driving the vehicle and started making a loud knocking noise and had a loss of power.

NHTSA ID

11763861

Incident

Aug 28, 2026

Rattling, knocking sound from the 6.2 ltr motor. Dealer verified engine failure, needs to be replace. Engine failed with only 4770 miles. Never made it to the first oil change.

NHTSA ID

11762965

Incident

Sep 3, 2026

Complete engine failure. Had to get the engine replaced with only 2,700 miles on it. Back in the shop on 9/5 to fix the engine again.

NHTSA ID

11762681

Incident

Aug 17, 2026

Three times this has happened. Most recently Pulling in drive and jumps out of drive to park with a jerk and stops.

NHTSA ID

11762573

Incident

Sep 5, 2026

XXX Pulling into Mason Park - Truck Shot down while driving. Went into Park (immediate stop) 2 of my Kids were in the truck at the time. Restarted truck and loud Noises. Immediately backed into parking space shut down and towed. Sent to dealership XXX Called spoke co/ Mark. [XXX] had tech. look at truck. expressed My concerns and Should Never occurred @ 6788 miles. Expressed Something Needs done. Recommend contact GMc. - Call GMC, Crated a Case #XXX. Engine replaced after 2 months. No one checked the transmission or had explained why it went into park while in operation.Refused to look at any other concerns. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11761659

Incident

Apr 22, 2026

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)

NHTSA ID

11760724

Incident

Jun 10, 2026

We were told when we purchased our 2026 GMC Sierra 1500 that all the engine problems have been remedied. Purchased our new truck January 3, 2026 put 2001 miles on the truck went on June 29. The engine suddenly just stopped while driving on the highway. We were able to pull over unable to ever get it to start forced to have it towed to a nearby GMC dealer where it has been ever since were told it had to have a complete new engine put in we have corresponded with General motors on three different occasions we still sit with no offer as we did apply for a lemon law buyback but General Motors continues to sell these vehicles which is very deceptive and misleading as this situation was not remedied in any 25 or 26 models.

NHTSA ID

11760716

Incident

Jun 29, 2026

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.

NHTSA ID

11760220

Incident

Aug 6, 2026

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.

NHTSA ID

11759857

Incident

May 28, 2026

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.

NHTSA ID

11759533

Incident

Aug 23, 2026

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.

NHTSA ID

11759373

Incident

Jul 29, 2026

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

NHTSA ID

11759354

Incident

Aug 24, 2026

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.

NHTSA ID

11759298

Incident

May 3, 2026

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)

NHTSA ID

11759297

Incident

May 3, 2026