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.
2026 GMC Sierra 1500 engine complaints
Page 2 of 5: complaints 11 to 40 of 102, newest first, as owners wrote them.
On September 29, 2026, I was driving my GMC Sierra 1500 on the highway at approximately 15 mph due to construction when the truck suddenly lost acceleration. Engine warning messages appeared, the vehicle automatically shifted into neutral, and the engine completely shut off while I was driving. A message instructed me to restart the engine. I attempted to restart it, and the truck eventually turned back on, although it was difficult to start. I was able to carefully drive the vehicle home. This was extremely concerning because the sudden loss of propulsion and engine shutdown occurred while I was on a highway and could have caused a serious accident, especially at normal highway speeds or in heavier traffic. I took the truck to Cavender GMC on September 30, 2026, for inspection and diagnosis. Still pending on results. I am especially concerned because there are ongoing the federal safety agency investigations, consumer complaints, and litigation involving certain General Motors vehicles and reported engine failures that can result in sudden loss of propulsion. Some reported incidents involving GMC Sierra 1500 vehicles describe symptoms similar to what happened to my truck, including loss of acceleration, shifting into neutral, engine shutdown, warning messages, and the need to restart the vehicle. I understand that my truck may not necessarily be affected by the same issue or included in any lawsuit. However, because of the similarities, I am requesting that GMC and Cavender GMC thoroughly investigate whether this incident is related to any known engine, powertrain, electrical, software, or safety issue affecting this vehicle. I am requesting that the underlying cause be identified and properly repaired before the vehicle is considered safe to return to service. My primary concern is safety, and I need confidence that the truck will not unexpectedly lose propulsion, shift into neutral, or shut off again while I am driving.
The 6.2L engine died at 8,300 miles. It took the dealership 6 weeks and would not give me a repurchase lease buyback. They put a new engine in, but I’m hearing that they didn’t really fix the problem and this is just a new version.
The powertrain/transmission is malfunctioning. The vehicle shutters, vibrates, and surges forward when coming to a stop, as if it wants to take off on its own. These symptoms began within the first couple of days after purchasing the vehicle on XXX. The valve body was replaced, but the issue continues. The vehicle is available for inspection. GM Case Number: XXX Dealership TAC Case: XXX This creates a serious safety risk. When stopping, the truck shutters and unexpectedly tries to lunge forward, which could cause a collision with another vehicle or pedestrian. The unpredictable movement makes it dangerous at intersections, stop signs, and in traffic. The dealership has reproduced the issue multiple times and performed diagnostics, but the shuttering and surging continue. The vehicle was last inspected around XXX. On XXX, I called GM to speak with [XXX] for an update on when a GM representative/technician would inspect the truck. I was told the case had been closed even though no resolution or inspection occurred, and [XXX] never called me back. No other agencies have inspected it. There were no warning lamps. Symptoms began within days of purchase and include shuttering, vibration, surging forward when stopping, and inconsistent acceleration. These symptoms occur daily and have worsened over time. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Dealer confirmed 6.2 V8 engine failed at a little over 4000 miles. Dealer stated it was the bottom of the engine. Probably the same failure the 21-24 recall is for.
I was driving home on the evening of September 12th 2026 and when I exited the interstate and came to a stop at the traffic signal my vehicle died and I had to have it towed. There was no way to flat tow because we couldn’t get it into neutral without the vehicle’s engine running. Once the vehicle’s engine died it would not restart. Had this happened while still on the interstate causing my vehicle to be disabled in the lane of travel it could have been deadly since it was 10 p.m. in the evening and dark outside. Anyhow had the vehicle towed to the dealership for diagnosis and the engine spun #7 rod bearing which ruined the entire engine at just 15,182 miles.
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.
I purchased this vehicle on May 28th 2026. At that time I was told there were no problems with the 6.2L engine. The problems they have had didn't affect the 2026 Denali 1500 6.2L's. After hearing about numerous 25's and 26's engine failures I decided to have my first oil change at 1540 miles. I asked the dealership to give me the oil filter so I could open it and examine it. I found excessive metal in the filter, indicating to me that the engine is failing. I contacted the dealer, they told me to go to GM Customer service. They told me there is nothing they can do unless the check engine light comes on or there is noise in the engine or it blows up. In which case people have reported traffic hazards getting to the side of the road without power or even the rear wheels locking up. One incident shows the vehicle had a fire and completely burned up. I made a vacation trip without incident and put another 825 miles on the truck, at which time I swapped out the oil filter and opened it up and found more metal particles. Common sense tells me that the engine is self destructing and will at some point fail. The manner in which that happens is the safety issue. I have reported this issue to the dealer and GM and they say just keep driving it. Putting myself and my family at risk. I know I am not the first one to have a bad engine in my new GMC Denali. There are just way too many defective engines in these vehicles to feel safe after buying such and expensive vehicle. Don't get me wrong, I love the truck!! I just would like to know it has a dependable engine to keep me safe while driving it!!
2026 GMC Sierra 1500 Denali 6.2L , with 3550 miles; started ticking and another mile to get home started knocking, had truck for less than a month, had it towed to the dealer they said will get a new engine, they can't even five me a time frame for the new engine replacement.
2026 GMC Sierra 1500 Denali 6.2L , with 3550 miles; started ticking at 45 MPH and another mile to get home started knocking, had truck for less than a month; no warning lights. I had it towed to the dealer. They said it needed a new engine, no time frame for repair.
With 10000 miles on my 6.2 liter the engine failed. Cause was main bearing failure. Needed full engine replacement.
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.
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.
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 the federal safety agency Action Number: EA26005 (ENGINE). The dealer was contacted. The failure mileage was approximately 160.
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.
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.
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.
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."
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.
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.
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.
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.
Was driving the vehicle and started making a loud knocking noise and had a loss of power.
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.
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.
Three times this has happened. Most recently Pulling in drive and jumps out of drive to park with a jerk and stops.
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)
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)
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.
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.
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