Table 1 shows one common engine and engine cooling related problems of the 2026 GMC Sierra 1500.
| Problem Category | Number of Problems |
|---|---|
| Engine And Engine Cooling problems |
Three different times now (most recent: 10/22/2026), I have had my truck completely shut off when coming to a stop on the highway/interstate. I always have auto start/stop disabled when I drive. When it happens, a message shows on the dash that says press start button. No other codes or check engine light. Thankfully it has started every time, but this is obviously a serious safety concern. After the second time it happened, I had the dealer (woodhouse Buick GMC omaha) look at it on 9/14/2026, but they couldn't find anything since there were no codes. I'm not sure if it is an electrical issue or this is related but my audio will stop working at times as well. Nothing from the radio or any blinker sounds. Sometimes it's static with a high pitch noise. 2026 GMC sierra elevation 5. 3 ecotec3 v8 10 speed.
I had driven about 30 minutes on the interstate at highway speeds and had just exited the interstate and the truck made a horrible noise, shut off, and the transmission threw itself into park at about 10 mph. At this time, the engine did not want to restart, but did eventually and I had a check engine light on, but I was able to move the truck out of the intersection so that I could be towed to the dealership. Prior to the incident, there were no check engine lights and the vehicle had only been serviced at a GMC dealership. I was very uncomfortable with the way the truck stopped and slammed into park. I am happy that no one was behind me, but it could have been bad. The vehicle has not been inspected yet to my knowledge.
While driving the truck it randomly shuts down, message on dash says shift to park to restart. No check engine light comes on or any other message. When it does this, the truck goes into park. It has been to the dealership 3 times and has not been fixed!.
On 10/15/2026 I was making a slow right-hand turn up a slight incline into a parking lot when the vehicle braked very hard and the transmission made a grinding noise. I looked at the dashboard, and it was showing that the truck shifted into park while I was driving. The electronic brake engaged as well. I tried putting the truck back into drive, but it would not go into drive. On the dash there was a service transmission warning. The push to start engine button still had the green led on as if the vehicle was running. I pushed the start engine button and the engine started (I didn't realize until now that the engine had shut off). At this point the truck would shift into drive. Another point of note is that I had turned off the auto stop feature. I do this every time I start my trip. The truck will be looked at on 10/16/2026 by the dealership. I did report the problem to the service department of the dealership. This incident was the first time it ever happened and there was no warning.
I was approaching an intersection about to make a left turn as the turn signal was flashing yellow and my truck just stopped accelerating. If I had taken that turn I would have got hit and most likely cause a huge pile up because the amount of traffic going through. I put my hazard lights on and tried shifting my truck into park, and then back into drive, and it would not accelerate. I had to turn my truck off and on a few times for it to accelerate. There were no warning lights on my dash and the truck is brand new.
Engine had catastrophic failure at only 1,433 miles driven. Incident happened on the interstate and truck was required to be towed to the dealer. Dealer said engine replacement is necessary.
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.
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 NHTSA 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.
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.
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.
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.
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.
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.
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.
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 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.
I am writing to formally request that general motors repurchase my 2026 GMC Sierra 1500, currently with approximately 9,445 miles, due to a serious and unresolved mechanical defect that poses a significant safety risk. Since purchasing this vehicle, I have experienced four separate incidents involving a complete and unexpected loss of engine power, causing the truck to become inoperable. In each instance, the vehicle suddenly lost propulsion and came to a stop without warning. While three of these events occurred while operating the vehicle near my residence, one incident occurred while I was attempting to merge onto a highway. Fortunately, traffic conditions at the time prevented a collision or serious injury. However, the sudden loss of power while entering a highway created an extremely dangerous situation and exposed both myself and other motorists to substantial risk. The vehicle has now been at the selling dealership for nearly one month while technicians attempt to diagnose and repair the issue. To date, I have not been provided with a definitive root cause or a permanent corrective action. The lack of resolution, combined with the recurring nature of the defect, has resulted in a complete loss of confidence in the vehicle's safety and reliability. My concerns are heightened by information suggesting that similar issues may have been experienced by owners of comparable GMC sierra vehicles. Regardless of the ultimate root cause, the fact remains that my truck has repeatedly exhibited a condition that can unexpectedly disable the vehicle while in motion, creating an unacceptable safety hazard. I purchased this truck with the expectation that it would provide safe, dependable transportation. Unfortunately, after four loss-of-power events and an extended period in the repair facility without a successful resolution, I no longer believe this vehicle can safely fulfill that purpose.
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.
Three times this has happened. Most recently pulling in drive and jumps out of drive to park with a jerk and stops.
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.
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.
Was driving the vehicle and started making a loud knocking noise and had a loss of power.
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.
Rocker arms replacement at 5,000 miles on my truck. Palm harbor tasca GMC.
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.
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.
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.
Vehicle: 2026 GMC Sierra 1500 at4 (3. 0l lz0 duramax diesel) current mileage: ~16,500 miles check engine light status: no check engine light active description of incident & symptoms: •interstate incident: while driving at highway speeds, a severe drivetrain vibration occurred (felt like a rear wheel weight flew off). •dashboard warnings: within 5 minutes, intermittent "traction control" and "forward collision warning" alerts appeared on the dash, accompanied by a sudden drop in engine power. •engine noise & idle: once safely pulled over, the engine exhibited a loud mechanical knock and a very rough, unstable idle. •extended crank: after shutting the engine off and waiting a few minutes, restarting the truck took roughly twice as long as normal (long crank/delayed start).
Engine completely failed and had to be replaced.
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.
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 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.
Driving on the highway near rockport, wa, when vehicle suddenly loss propulsion, engine light appeared, and vehicle went into transport mode enabled. Without causing an accident, I was able to pull to the side of the road. Once I put vehicle in park, it shut off and displayed, “tranport mode on. Vehicle would not start and was towed home. My son-in-law was able to disable transport mode, but vehicle still will not start. Will notify dealership on Monday.
The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving 70 mph and depressing the accelerator pedal, the vehicle started decelerating unintendedly. The message “engine power reduced” was displayed. A dealer was contacted. The vehicle was taken to a dealer where it was diagnosed and determined that the engine needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure and opened a case. The approximate failure mileage was 6,028.
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.
I was driving on 96 w. In slow traffic on the freeway when the vehicle put itself in neutral and shut off.
6. 2 l just blew up per dealership.
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.
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.
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.
I have a 2026 GMC Sierra 1500 with the 6. 2l engine. I purchased it on [xxx]. On [xxx] with 13,000 miles on the truck the engine started making a bad noise from the lower end of the motor. I immediately took it to the dealer randy wise Buick GMC in fenton michigan. They diagnosed it as a spun bearing and had to replace the engine. I just got it back today August 7th 2026 information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).
The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving 45 mph and depressing the accelerator pedal, the vehicle slowed down unexpectedly. The vehicle then lost power while stopped at a traffic light. No warning light was illuminated. The vehicle was turned off and restarted, and the vehicle operated as intended. The vehicle was taken to the dealer, where it was diagnosed and determined that there were metal shavings inside the oil pan and the engine needed to be replaced. The engine was replaced twice. The manufacturer was not notified of the failure. The approximate failure mileage was 3,202.
While traveling from [xxx] to [xxx] for vacation, I was in [xxx], and when I pulled off the interstate and came to a stop sign the vehicle quit. At first, I was unable to restart the vehicle, but after sometime I got it started and was able to pull it off the road while the engine was making very loud clattering noise and the vehicle would not stay running. Prior to this there were no warning, lights or indications that the engine was going to quit. I checked the engine oil and it was full. I had the vehicle transported to a GMC dealer in [xxx], where it was diagnosed as requiring a new engine. The vehicle is a 2026 GMC Sierra 1500 denali purchased in December 2025 and has 8,865 miles on it. A little over 4000 miles I had the vehicle oil changed at starling GMC titusville FL. At the time of my service visit, I asked the service writer, [xxx] to check the engine idle because at times it seemed to run a little rough and it quit while pulling in my driveway one day. [xxx] advised me that there is no idle adjustment on the vehicle, so I said I’ll just keep an eye on it. There were never any indications of an engine problem prior to this or even as of now there are no warnings displayed on the instrument panel. I also subscribe to onstar and it indicates everything in the vehicle is normal with no issues. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).
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.
2026 denali, 6. 2, failed after getting off express way while on my way for a fishing get away and pulling my boat. No warning lights, noises, nothing. Came to a stop sign and at the last second slammed into park. Dash went black, 10 seconds later would come back on and try to start, then the dash goes black. Sheriff pulled up 20 or so minutes later and told my wife to get back into the vehicle as she was directing semis and other cars to go around. Towed to a chevy dealership 13 miles away. After running tests on the truck, came up blown engine. 7600 miles. 5 hours later we left with a loaner and able to continue on with our plans. I do thank the dealership for their help and loaner. 23 business days later they delivered my truck to my house and returned in the loaner. After all my investigating on these engines, I will not be buying another one. Time for gm to invest some of their profits into finding the problem!.
While driving vehicle the engine lost power and shut off in traffic. There were no warning signs of issues at that time. The dashboard went blank and then reappeared and the truck was in park. After that the truck would not shift gears. The truck was towed to the dealership and found to have had catastrophic engine failure.
With 10000 miles on my 6. 2 liter the engine failed. Cause was main bearing failure. Needed full engine replacement.
I bought the truck with 2 miles , shut off on me within 1,300 miles wouldn’t turn on , supposedly it was a bad fuse that was burned out , second time it shut off on me again , all my sensors were going off and on and truck wouldn’t turn back on , they told me they couldn’t figure out the problem evaczue they had disconnected the battery and it erased all the codes 3rd time , they changed my oil and they forgot to torque the screw back correctly and all the oil spilled and cost my engine to lock up and mess up , they replaced the motor with a new one 4th time , supposedly it needs a replacement for a catalytic converter which is being replaced now as we speak or sometime this week.
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.
My motor has a catastrophic failure. Started sputtering and squealing.
2026 GMC Sierra 1500 at4x with 3898 miles. Driving 71mph on state highway on flat grade road. Lost power and vehicle shut down after pulling off the road. No previous lights or warning signs prior to power loss. Vehicle would not start afterwards. Onstar diagnostics sent ecm engine and transmission system code p0016. Had vehicle towed 100miles to gm dealership. Upon inspection of vehicle, the service department contacted me the following day and said the the vehicle needed an entire engine replacement according to gm cooperate. I asked if it had anything to do with the 6. 2l v8 l87 engine problems from previous recall years of 2021-2024. Service tech stated yes it was more than likely the same issue. Very unhappy with my new gm vehicle purchase. Will have to have a full engine replacement before my first oil change!.
Catastrophic failure of engine while exiting the interstate.
Sudden catastrophic engine failure occurred at 7400 miles, 2026 GMC sierra1500 denali with 6. 2l engine. Driver and 3 children in vehicle headed to school when engine suddenly failed while driving on the roadway. No warning or vehicle symptoms prior. We were told the truck needs a total engine replacement- on a brand new vehicle. It has been nearly 9 weeks with no resolution or repair from gm. The truck was towed to the gm dealership it was purchased from on June 18th and it remains sitting in their service department lot with no timeline for repair or replacement.
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 approximately 45 mph, I slowed to make a right turn into a parking lot. The engine suddenly stalled and lost all propulsion. The vehicle retained electrical power but automatically shifted into neutral, and would not shift back into drive. I braked to a stop, temporarily stranding the vehicle and blocking traffic in the parking area. Attempting to turn the vehicle off via the start/stop button actually restarted the engine, confirming the stall. The truck then shifted into drive and operated normally. A subsequent onstar diagnostic scan found no active trouble codes.
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. ".
Total engine failure on 5/31/26. Truck lost engine power while on highway and had to be towed to dealership where they found the lower end of the engine failed. Engine and radiator replacement needed, both are backordered with no eta.
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.
While driving on the highway, the steering became much more stiff, and then I heard metallic clanging sounds for a few seconds. The dashboard said press start to start vehicle. I pressed start while going 30 miles an hour and all lights and instrument clusters went black. I pulled into the grass median where the truck would not start or shift gears. Truck was towed to a GMC dealership.
Sudden catastrophic engine failure with only 6000 miles on vehicle on may 26, 2026. 2026 GMC Sierra 1500 at4x with known defective 6. 2l l87 v8. Had to coast across three lanes of traffic to get to other median as highway location was on large curve. Someone very easily could have been hurt or killed.
Heard clanging noise under hood as I was driving and truck just stopped. Tried to restart and nothing! towed to dealership where they found the engine has to be replaced.
I was driving on interstate 95 at approximately 70 to 75 mph when I lost all power and compromise steering with tractor trailer behind me god willing I was able to pull over to the shoulder. My safety was compromised and I lost all faith in GMC. My vehicle has been out of service for 27 days at this point while waiting for an engine replacement with no eta on service. According to pennsylvania lemon law after 30 days a lemon law claim can be submitted.
The contact owns a 2026 GMC Sierra 1500. The contact stated while driving 40 mph, the vehicle independently engaged into limp mode. A dealer was contacted. The vehicle was towed to the dealer where it was diagnosed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was not notified on the failure. The approximate failure mileage was 10,000.
5/08/2026: I stopped outside my garage. I then placed the truck in park and exited the vehicle while running. I went inside my garage and several minutes later, heard a crash. The truck had driven forward while unattended, and crashed into the corner of my garage, causing damage to both the building and the truck. Truck indicated it was still in park upon reentry. 5/11/2026 in a separate incident 3 days later, while driving at approximately 50mph, truck engaged in an automatic braking event with no discernible cause. Simply applied what felt like 100% braking for a split second, then released. 5/12/2026: truck taken to GMC for investigation. No codes in any modules detected. 9/20/2026: vehicle reports transmission fault, states it should not be driven. 9/21/2026: towed to GMC dealer. Found codes p17a8 and p189d and diagnostic code 6906361, internal fault within gearshift control module. Requested GMC pay for damage resulting from collision, as clearly the unattended driving appeared related to gearshift control, but was refused. GMC stated that unattended driving was not possible and did not result from the detected failures.
Engine died while driving at higher speed on interstate. Barely able to pull to emergency lane before truck stopped. No warning of any issues with it. Had towed to dealership. Dealership confirmed 6. 2 engine was faulty. Engine replaced under warranty. Truck only had 1207 miles on it when engine died.
I bought a brand new 2026 1500 GMC sierra at4x and after 1,800 miles the engine seized and failed.
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.
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.
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).
6. 2 engine blew up 3000 miles.
I bought the truck brand new from gregg young in atlantic, IA. While an hour into the drive home, the truck began shuttering as if the transmission was having problems finding the gear. I immediately made an appt with their parent dealership of gregg young in plattsmouth, ne. They had the truck for a week and couldn’t duplicate the transmission issues after I reported several occurrences and symptoms, they also didn’t provide a service invoice of the work performed while I found was unusual. As I was driving the truck home from repairs it started hesitating and having difficulty finding gears. I didn’t think much of it since the dealer claimed there was nothing wrong. This past weekend while going 65 mph down the freeway the transmission started shuttering as well as the truck and the tires began to lock up to the point of almost losing control, there was also metal on metal noises. I had to pull over and luckily driving real slow I made it home. The gregg young dealership were I bought it will take no responsibility and provided falsification since no service was provided nor upon checking app gps there was no indications it left the dealership while in there possession for a week, will contact GMC in the am since this has now become a safety issue and there was metal on metal contact noises and the serious risk of a crash.
Complete engine failure at 1838 miles. Need complete engine replacement. Estimated time unknown for replacement parts.
The motor on my 2026 GMC sierra stalled 2 weeks ago with a p0016(crankshaft position sensor issue). Was able to clear code and limp home. Vehicle did stall on a busy road and stop abruptly. Scheduled service and was advised to drive it in. Was experiencing irregular idle when warmed up, and a slight hesitation in the pedal. Service advisor started the vehicle and claimed no codes, and everything appear ok. Later in the afternoon the service advisor called to inform me that the vehicle had a siezed engine and had siezed during a test drive on the highway. Currently waiting on warranty information, and engine replacement information but I've been informed it will require a whole new engine. This is the same 6. 2l l87 v8 that has been in near constant recalls from GMC over the last 6 years.
The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, there was an abnormally loud and rough knocking sound coming from the engine block. The oil pressure decreased to zero, and the engine seized. There was no warning light illuminated before or after the failure. The vehicle was towed to a dealer, where it was diagnosed with a blown engine. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 5,018.
Engine lock up with 5018 miles on, it is a the 6. 2 motor rod and crank bad.
The engine started having knocking and I took it to the dealership and now I have been waiting 45 days with no engine replacement in site after they told me the engine failed completely. It had 3,900 miles on the engine!.
I am the owner of a 2026 GMC Sierra 1500 denali ultimate equipped with the 6. 2l v8 l87 engine (VIN: [xxx] ), purchased new approximately three months ago. I am filing this complaint proactively. I have experienced no engine failure or symptoms to date. However, I am filing based on a documented pattern of l87 engine failures in 2025 and 2026 production vehicles, confirmed by multiple gm dealership technicians, which suggests that the manufacturing defect underlying NHTSA recall 25v-274 may not have been fully resolved by gm’s stated production improvements dated June 1, 2024. Nhtsa recall 25v-274 (April 2025) covered 597,630 vehicles from model years 2021–2024 for catastrophic l87 engine seizure caused by connecting rod bearing failure and crankshaft defects. Gm excluded 2025 and 2026 model year vehicles based on a claimed manufacturing fix. However, multiple 2026 production vehicles have since experienced the same bearing failure at extremely low mileage. Open NHTSA investigation ea25007 is already examining vehicles outside the original recall window, and recall query rq26001 is investigating the adequacy of gm’s remedy. I am requesting that NHTSA consider expanding the investigation scope to include 2025 and 2026 model year vehicles. As a 2026 owner of a $90,000+ truck with the identical engine configuration, I believe my vehicle warrants inclusion in any expanded investigation or recall action. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).
We bought the vehicle on February 28th and on march10th my husband was driving on his way to work on the i95 highway and the engine shut down. My husband was in the middle of the highway with a speed limit of 65. Traffic was able to slow not to cause any more accidents however he had to be towed and gm replaced the engine. Because it had not been 30 days in the shop. Due to gm abiding by lemon laws we were not able to qualify for a buy back. We have been fighting with them ever since. I was able to get a reimbursement of my first car payment. However, my husband is a general contractor and is absolutely terrified to accept jobs far away because we don’t know when the truck engine might give up again. All of the charging ports stop working a couple of weeks ago, we had to take it in for repairs. This is a $78,000 vehicle with 4 miles on it when we purchased it. I don’t know what it is worth now because the engine was replaced with in 10days of purchasing it. I need help!!!!!!!!!!.
Driving on the PA turnpike at speed with traffic and the engine lost power and started squealing. No lights came on, I was able to get to the side of the road and the truck shut off. When I restarted it, it sounded terrible. Had it towed to dealer and dealer stated that the engine had a terminal failure with the crank bearings and needs replaced. I was fortunate at the time of the issue that I was able to get off the road since the truck lost all power.
Driving approximately 30mph, the engine shut down. Vehicle shifted into neutral until stopped and shifted to park. Unable to place in neutral to pull off the road. Check engine stated transmission needed service. Dealership states seized engine. Engines are on back order. Vehicle has 2980 miles on the odometer. I'm active duty navy and have a permanent change of station this summer and no vehicle to move in and I also haven't gotten a rental.
My 2026 GMC sierra at4 1500 6. 2 l87 engine had a catastrophic failure with only 3347 miles. It stalled twice while driving home, when pulling into my driveway it stalled a third time and would not start after that. Before having my vehicle towed to the dealer from my home I connected my code reader and it posted code p0016. After being diagnosed by the dealer they informed me I needed an entire new engine. There were no warning lights or message prior to this failure my vehicle was purchased 9 week prior.
I stopped at a red light in the middle of a 50 mph intersection when the light turned green the engine completely shut off, and it didn’t want to turn back on. I was stuck in the middle of the intersection in a very high risk area, putting myself and other drivers at risk. Onstar diagnostics didn’t report any issues with the truck. According to their diagnostics, everything should have been running perfectly fine. The motor shut down completely and we weren’t able to shift the truck into neutral in order to try to move out of harms way. There was no warning lights or anything before this happened. The first tow truck driver that came by was told that he was there “in order to do a jumpstart” he ran a diagnostic on both of the batteries and said that they were perfectly fine. Another tow truck had to be dispatched since the first wasn’t equipped to take the truck. In total we were stuck in the middle of the intersection for almost three hours. The amount of times we almost had someone crash into us during that time was very concerning. Dashboard and lights were all working perfectly fine. Auto start stop technology seems to have shut down the motor and was not able to get it to turn back on . This vehicle is a safety hazard.
Engine failure at 18,000. Knocking noise started immediately followed by vehicle going into low power mode. Dangerous to drive in traffic in low power mode. No other warning lamps or indications that something was wrong. Dealer inspected and found a bearing went out in the engine.
My engine seized up on me on the highway. I was stranded and couldn’t start the vehicle and it was freezing outside.
I was out of town and driving on the highway around 75 mph, when the motor suddenly lost all power. I was driving in the far left lane approaching an overpass. The sudden loss made it next to impossible to make it off the overpass on a very busy freeway safely while trying to navigate many cars trying to pass me . The truck came to a complete halt on the white shoulder line, 50' off of overpass sh 31. The truck would not restart or do anything I could not push it any further off road. I excited the e truck and stood off the freeway for my safety, as the truck was on very edge of freeway. GMC roadside assistance took my truck to nearest dealer. This occurred on a Friday, dealership gave me a loaner car to get home as I was from out of town. They stated it would probably be the following Tuesday maybe Wednesday before they could tell me anything. I never heard from dealership service department, so I called them on Thursday morning and was told my truck motor had seized up and a new motor was needed. Service advisor stated GMC had been contacted and paper work started and I would be getting a new motor. The service advisor also stated that he had called and left a message. We verified my phone number and he had correct number, however I still never receive a call or voice mail. I still have not received any documentation on the failure or a repairs needed.
While driving on the highway my 2026 GMC Sierra 1500 denali ultimate the vehicle lost propulsion and the dashboard went dark because it shut off. I was exiting the highway onto a skybridge and rolled to a stop before reaching the top on the skybridge. Vehicle would not start again and needed to be towed. Dealership concluded my 6. 2l v8 engine needed to be replaced due to crank shaft seizing. Engine had 1861 miles. This put me in a very dangerous situation due to the limited space on the skybridge with passing traffic.
Vehicle stalled in busy intersection in mckinney texas , unable to start are shift into a neutral position on transmission to remove from extreme dangerous intersection, sheriff advised that road side assistance that was contacted is not going to be in time (90min)to keep from causing an ongoing traffic backup , sheriff dispatched their own towing service to resolve the situation from getting extremely dangerous . Vehicle and my wife was towed to mckinney Buick GMC dealership.
"vehicle exhibits a severe rpm flutter and rhythmic harmonic vibration at idle. These symptoms are consistent with manufacturing defects in the connecting rod and crankshaft currently under NHTSA rq26001 and ea25-007 investigations for the gm 6. 2l l87 engine. The defect presents a substantial risk of sudden engine seizure and loss of propulsion while driving. Vehicle is currently out of service at jim curley GMC for its first repair attempt. The dealer has stated repairs will not begin for several days. ".
"vehicle is experiencing symptoms consistent with the 6. 2l l87 engine bearing failure investigation (NHTSA 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.
Odd noise from bell housing area at 1200 miles that went with engine rpm. Took the truck in to the dealer and they said they couldn't recreate it but to bring it back in if it returned. Jan 27th at 5200 miles on the truck, I was driving down the highway at 60mph and got a reduced acceleration message on the dash along with a check engine light. Brought it to the dealer and was informed it was a bad thrust bearing and needed and engine and turbo replacement. Still waiting for the truck to be done.
The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle made an abnormal sound and failed to accelerate as needed. There was no warning light illuminated. The vehicle was taken to the dealer, who determined that the engine needed to be replaced. The vehicle was not repaired and remained with the dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 6,000.
Total engine failure at highway speed with loss of propulsion . Catastrophic engine loss with 3,000 miles . GMC never fixed the problem with the 6. 2 l87 like they said.
2026 Sierra 1500 at4 with 3. 0l duramax diesel. Three major issues. 1. 2960 miles, thrust bearing failure caused low oil pressure and internal damage. Vehicle needs complete engine replacement. The truck is still at the dealer with no eta on engine arrival and replacement. 2. Vehicle has severe electrical issues. Battery replaced on second day of ownership due to over charge and smoking. The truck would randomly lose the ability to produce sound through infotainment system on start. This includes warning sounds and audible turn signal sound. Dealer said it’s caused by faulty amp which was replaced. 3. The truck shut off (full system shutdown) and the transmission failed over to neutral while driving on the highway and failed to restart. Barely restarted on second attempt. Dealer has no idea why it is doing it. However the vehicle was throwing multiple code related to transmission module failure, brake module failure, transmission module failure, etc.
I heard a loud metallic knock that was not consistent with normal engine noise. I noticed the oil pressure was on the lower end of the scale but not abnormal based on how it is displayed. I decided to take the vehicle to the dealer ASAP for an oil change (that was coming due) and discuss with them. I drove roughly 20 miles from start of noise until delivery at the dealer. The truck gave me a "reduced acceleration, drive with caution" message 10 miles prior to the dealership but no associated lights, engine codes, check engine light or associated alerts on the mygmc app. Dealership found oil pressure ranging between 4-8 psi, and a failed oil pressure control solenoid, heavy metal debris in the oil pan including parts of the thrust bearing and oil squirter. Entire engine and turbo replacement was required. Truck had 143 hours on the engine and 6,300 miles. It was produced in August of 2025 with a purchase date of 17 October 2025. Produced: 8/25 purchased: 10/17/25 failed: 12/30/2025 returned with new engine: 1/23/26.
On or about 12/14/25 at approximately 2,000 miles my engine began smoking to the point that it was pushing in to the interior of the cabin and created a cloud like atmosphere that smelled of burning oil. There were no warning messages in the vehicle or in the mobile diagnostic application associated with the vehicle. Once parked, I popped the engine and observed visible smoke from the engine and a distinct crackling noise coming from the area of the engine. I checked underneath the vehicle and was able to see oil dripping and, subsequently, feel oil running down a majority of the undercarriage of the truck. Ultimately, I had the vehicle towed the dealership and they diagnosed a front cover seal for the engine was leaking and repaired the issue. On 3/20/26 I had to take my vehicle in for an early oil change due to the above issue and low oil life. Since the above repair, I had continued to smell intermittent burning oil in the cabin of the truck. During the oil change I asked the gm service provider to check to ensure the same issue had not recurred and, following the oil change, I was informed they did not see any issue. On 5/8/26, at approximately 7,000 miles, the same issue regarding visible smoke in the cabin occurred and, upon opening the hood, I was able to see visible smoke from the engine and hear the same crackling noise. I checked underneath the vehicle and, again, was able to see oil dripping and feel it on a majority of the underside of the truck. There were no warnings, in the vehicle or in the gm app for the vehicle, associated with the failure. Again, I took the vehicle to the gm dealer service center. The diagnosis was a leaking rear cover seal. Upon repairing this issue, gm service discovered "flakes" in the oil in the engine and diagnoses a failing thrust bearing that indicated engine failure. I have documentation of the diagnosis and attempted repairs but, am not currently in a location that I can scan and upload them. I can provide them.
3. 0 duramax engine failure - 2026 GMC Sierra 1500 denali ultimate at just 6,755 miles and only 77 days of ownership. Within the first few thousand miles, the truck intermittently had warnings appear of “reduced acceleration, drive with care”. The truck would limit its ability to maintain speed. When it occurred during highway driving, it was particularly dangerous. The check engine light would also come on. After parking the vehicle for a bit and restarting it, things returned to normal. At the dealership, we reported the issue and leaned the computer reveled a p06dd code which required them to check the crankshaft for excessive play. Our truck was out of specification requiring complete engine replacement at just 6,755 miles. “service bulletin 25-na-307 which states this code may set due to thrust bearing failure. Following 25-na-307 checked crankshaft end play and got a reading of 0. 3400 in. The maximum spec is 0. 0124 in. “ gm and laura Buick GMC should not have sold this truck to us without inspecting it for this known issue. This extensive repair required complete removal of the cab from the chassis.
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.
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).
I do not have an official communication from the dealer who is servicing my vehicle. However, they have had my vehicle for almost 3 weeks and they tell me that the engine has failed and needs complete replacement. They said the engine lost compression and quit running, it now cranks and does not start. Although the engine has not been disassembled we believe the point fo failure to be in the rotating assembly of the bottom end of the engine.