general problems of the 2025 GMC Sierra 1500 - part 1

What component or system failed or malfunctioned, and is it available for inspection upon request? the engine/powertrain failed. The vehicle is a 2025 GMC Sierra 1500 equipped with the 6. 2l v8 engine. The engine developed a severe knocking noise and loss of power at approximately 5,545 miles. The vehicle was taken to the gm dealership, where an engine replacement was approved. The failed engine/component may be available for inspection through the dealership or gm, depending on whether it has already been removed or returned to the manufacturer. How was your safety or the safety of others put at risk? the engine failure created a safety concern because the vehicle experienced reduced power/loss of propulsion while being operated. This could have put me and other drivers at risk because a sudden loss of engine power can make it difficult to safely maintain speed, merge, tow, or move the vehicle out of traffic. The issue occurred at very low mileage and without enough warning to prevent the failure. Has the problem been reproduced or confirmed by a dealer or independent service center? yes. The problem was confirmed by a gm dealership. The dealer diagnosed the engine failure and gm approved an engine replacement under warranty. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? the vehicle was inspected by the gm dealership. Gm was involved in approving the engine replacement under warranty. To my knowledge, the vehicle has not been inspected by police or insurance representatives. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? prior to the failure, the vehicle developed a severe engine knocking noise and reduced power/lack of power. These symptoms appeared shortly before the engine failure at approximately 5,545 miles. I do not recall any specific warning lamps or messages before the failure, unless the dealership records.

Notice during startups and slow speeds engine making taping noises. After bringing my truck in for service I was told my sound was my lifters on the passenger side.

Rough idle started at 11,400 miles. Took to GMC dealer near me and had thrust bearing clearance measured. Measured . 0054"(within spec). They released truck back to me. 19,400 mile oil change found large metal(non magnetic) slivers in the filter media. I cut filters to check for issues due to known issues with this engine(metal). I called GMC corporate, I was told to not drive the truck. I paid out of pocket for the tow 142 miles away. Dealer told me they checked thrust bearing and came in at . 0055", no noises, and no check engine light. Idle is very rough on start up. Gm corporate stated a service advisor will call. Never got a call. I have sent and displayed the evidence and offered to show oil filter contents to both dealer and corporaten both have not done anything about this safety issue. This is a severe safety issue. Engine is highly likely to lock up and cause serious injury to both me, my family, and others on the road. Dealer has released truck back to me and my family with clean bill stating they didnt find anything wrong. They refused to see my documentation of metal slivers or the 3 rimg binder full of maintenance records. As of now I will be escalating this to higher up in GMC corporate. Severe safety risk for my family and everyone on the road. GMC dealers refusing to diagnose.

Either while stopping while driving or parking (forward or reverse) the engine rpms go up thus wanting to move the vehicle in that direction causing the breaks needing to be applied harder. When you shift into neutral the rpms go way up (3000). This has happened on this vehicle 3-4 times of which I have video of the latest occurrence. When put into r or d the rpms are still over 1000. This also happened on the courtesy vehicle same make and model) I was given but on this one the rpms went up to 5000 of which I also have a video. The dealership has not been able to duplicate the issue as of yet. My fear is that the vehicle will hit someone or something if the break isn't pressed to the floor. It happens very randomly. The dealer currently has my vehicle trying to figure it out. They say gm says there's nothing they can do. No warning lights or messages appeared.

In normal operation on Tuesday may 26,2026, the engine experienced catastrophic failure. The engine is the gm l87 6. 2 liter. This was on a highway in the country and I was able to maneuver the truck off the road before an accident occurred. It did leave me stranded and I was required to get it towed on a roll off (it was not drivable) to the dealer where I purchased it. The dealer [xxx] ) inspected my truck and has informed me that the issues with my 2025 sierra match the issues for the recall gm had for the model years 2021-2025. It will require a new engine, radiator, among many other parts. There weren't any previous warnings. A check engine light only came on once the engine was engine came apart. An oil change on the vehicle by gm was done a month ago. The truck is a 2025 and has approximately 6,600 miles is all. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

6. 2l crankshaft failed.

The engine blew.

15000 miles and the engine spun a bearing and the engine blew.

My GMC sierra at4 with the 3. 0l duramax diesel, has 1,500 miles on it, when the engine failed. I was traveling from [xxx] to [xxx] , towing a trailer, when the check engine light came, and the truck entered reduced power mode. It immediately slowed the truck without warning - which made for a very dangerous situation for all of the vehicles behind me and for my vehicle. After getting the vehicle and trailer to a dealer, disconnecting the trailer, and then getting the truck in the shop, the dealer defined the obdii code as being p06dd - engine oil pressure control solenoid valve stuck off. U0146 - lost communication with central gateway module, and u1605 - lost communication with side obstacle detection control module - right on private can bus. The dealer indicated that the p06dd code meant that the thrust bearing on the crankshaft failed and the engine would need to be replaced. The ending only has 1500 miles on it. It turns out that there are many gm 3. 0l diesel engines that have failed for this issue and that gm issued a technical service bulletin in 2025 for this issue - TSB 25-na-307. I work in the medical device industry and when there is a safety issue with your products - you initiate a recall. To date there has been no recall simply the TSB. What is the NHTSA going to do about ensuring that gm, and other manufacturers, are making engines safe? these engines can literally explode - sending metal shards through the engine into the passenger compartment. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

First occurrence was 02/27/2026 - onstar detecated a critical issue, the check esc, check tsc words came on in the center dash, then the orange lights came on and my truck went into limp mode at a stop light. I had to limp mode a mile to the nearest dealer. Where nothing was repaired just reset. Second occurrence - exhaust flap valve failed creating chirping noise resulting in a muffler replacement on 04/28/2026 - picked the vehicle up on 04/30/2026 third occurrence - 05/01/2026 came out after a wedding to start my truck which it immediately repeated the first occurrence, check esc, check tsc with the orange lights and chugging. Recorded on camera now the trucks been at the dealership awaiting updates.

The contact owns a 2025 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the engine made abnormal knocking sounds. No warning light was illuminated. The vehicle was taken to the dealer, who discovered metal shavings inside the engine oil and determined that the crankshaft bearings had failed. The contact was informed that the engine needed to be replaced. The vehicle was not yet repaired and remained with the dealer. The manufacturer was made aware of the failure. The failure mileage was 26,634.

I was traveling on the i70 west around the 210 mile marker. I was in the passing lane at high speed when the vehicle without warning switched itself off. The dash showed the “press start” warning, but the vehicle would not restart. I was fortunate that I was around 1/2 a mile from a rest stop area. I was able to glide the vehicle into the rest area. As I slowed close to a stop the vehicle suddenly stopped and applied the park brake. I am a very experienced driver, if my wife was driving, the vehicle shutting down completely in the fast lane could have been catastrophic. The road was busy. The vehicle was locked up in park and was unrecoverable. It had to be dragged sideways out of the area that it had come to a stop, and then dragged onto and off the tow truck. The following morning the dealership confirmed the engine was seized. When I purchased the vehicle, the dealership confirmed that the historic failures on the l87 6. 2l v8 engine were resolved. Clearly not the case.

I bought a brand-new GMC 1500 6. 2l at4 back in 2025. Never have an engine recall. At 39k miles, lost power, and ended up replacing the camshaft and lifters. 2k miles later went back to the dealer for engine replacement.

2025 GMC sierra 6. 2 l v8 engine failed by locking up or seizing. Heard pinging / knocking sounds while driving 3 miles from my home to the dealer. Engine shut off without warning, vehicle shifted to neutral. Coasted to a stop, attempted to restart the engine, would only crank. Dealer diagnosis is that the engine will need to be replaced. Sounds just like the 2021 - 2024 gm recall for this same engine. Vehicle has 11,670 miles on it. Safety risk: loss of all power while driving. No warning lamps or messages prior to engine failure.

Was driving truck and reduced acceleration drive with care comes up on dash pull over shut truck off start truck warning gone in 30sec back on and repeat drive off again then truck shut off while driving and try to start again and the dash went black motor did not turn over then tried again and same thing called tow company and had towed to dealership. Dealership said it had 2 pages of codes and now needs a new motor. . . . . . . . No estimated time on getting my truck back.

I was driving and the engine abruptly stalled. The truck self-shifted to neutral. Once stopped, I shifted to park to attempt a restart. It would not crank. I was on a 2-lane road so I did not have a shoulder. Once I realized it would not restart I tried to shift to neutral so I could push it to a subdivision road about 50 yards away only to find out my transmission has no ability to shift to neutral (the dealer confirmed this later). So I was stuck on the road for hours just over the crest of a hill with people coming up on me and my family at 50mph. It was a windy 10 degrees so we could not wait on the side of the road where we would have been safer. This is how people get killed; being stopped where people can't see you and do not expect you to be stopped. Why can I not get the truck off the road? if this happened on an 8-lane highway how would I get to a shoulder, even after traffic had stopped behind me? on top of all that, the problem with the truck ended up being an engine bearing failure (per the dealership service dept) that is a known problem with this engine and truck build date. General motors needs to proactively diagnose and get these engines replaced before someone gets hurt. There is a TSB issued for the bearing issue but when I asked my dealer about it a month ago, before the failure, they acted like they knew nothing about it and told me to bring it in if I hear noises. If they had offered to check the crankshaft endplay when I asked about it ( as the TSB suggests), I may not have gotten stranded and my family's safety put at risk. There were no warning lamps, and no strange noises before the engine seized. My fuel economy had decreased by about 20% in the last month but that may be from cold weather operating conditions. I have a separate electrical issue that I've been chasing down and I assumed this stall condition was related to that. But the dealer confirmed this was a bearing failure.

Driving at highway speed engine lost most power (limp mode), was able to get to an exit at low speed with flashers on but was creating a hazard on busy interstate. Dealer diagnosed truck needs new 3. 0 liter duramax engine per gm TSB 25-na-307, bad thrust bearing.

With approximately 5,200 miles on my new vehicle, received an error message on the dash while driving on 1/8/2026 that read “reduced acceleration; drive with care”. I immediately took the vehicle to a local gm dealership and was informed on 1/9/2026 that due to a faulty thrust bearing (covered under the non-mandatory technical service bulletin 25-na-307), the entire engine sustained a catastrophic failure and that the engine “tanked itself” and “grenaded itself”. Driving with the reduced acceleration mode active is beyond frightening as it’s very difficult to navigate traffic intersections in time to avoid oncoming traffic. It was also noted that it other cases where this faulty part causes the engine to totally fail, the vehicle becomes unusable at that point. I was informed that a replacement motor is not expected from general motors for at least 2-3 months as this is becoming a more prevalent issue with certain 2025 sierra’s with the 3. 0 duramax diesel motor.

I bought my truck new in June 2025. On the night of December 29, 2025, with around 9,300 miles on the odometer, I began to hear a knocking sound coming from the engine while I was driving it back to my house from my mother's house. The sound got progressively louder and louder. The truck eventually displayed a "reduced acceleration drive with care" warning. I thought catastrophic engine failure was imminent and did not believe I could make it home. I called my in-laws (they were closer to my location than my house), agreed to park it there overnight, and thankfully made it to their house. The next day the truck was towed to the GMC dealership. A week later, GMC diagnosed this issue as a thrust bearing/crankshaft issue and agreed to replace the entire engine. A crankshaft issue in a new diesel engine should not occur, yet it did. My vehicle is currently being repaired, so the dealership said they had no repair records to provide me. This is the link to the video of the sound it was making after I made it to the in-laws: [xxx] I had just dropped off my [xxx] child with my mother about twenty minutes earlier. I was extremely close to being stranded on the side of the highway at night in the December cold with a [xxx] baby. Thankfully, that did not happen, but it was a close call. My cousin also has had a similar issue with the exact same make and model of his truck. I believe this engine is not being manufactured according to the design specifications and it is a danger to the public until the manufacturing issue with the supplier is adequately corrected. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The contact owns a 2025 GMC Sierra 1500. The contact stated that while driving at 35 mph, there was an abnormal knocking sound coming from the engine. No warning lights were illuminated. The vehicle was towed to the dealer, where it was diagnosed with a rough idle code, and that the thermostat coolant housing had failed. The contact was provided dtc codes: b1a76 with failure code 0x15 (pending), p05d, u0075, u0101, u0146, u020c, u0265, u1614, and u1616, and the codes were active. The vehicle was repaired. The contact picked up the vehicle from the dealer after hours, and when the contact started the vehicle, the abnormal knocking sound was still coming from the engine. No warning lights were illuminated. The contact stated that when the a/c was turned off, the abnormal sound ceased. Additionally, the contact performed the oil changes on the vehicle and noticed that the engine was consuming an excessive amount of engine oil. The contact stated that there were no oil stains on the ground. The contact needed to add oil every 800 to 1,000 miles driven. The vehicle was taken to o'reilly's Chevrolet, located at 6160 e broadway blvd, tucson, az, for a diagnostic test, and it was determined that the air compressor had failed. The vehicle was not repaired. The vehicle remained at the dealer pending the repair. The contact stated that when the a/c was activated, the knocking sound in the engine compartment returned. The manufacturer was not made aware of the failure. The failure mileage was approximately 18,000.

The contact owns a 2025 GMC Sierra 1500. The contact stated that while stopped at a traffic light, the gear shifter was shifted to park(p) and the vehicle stalled. The message "start engine" was displayed. The vehicle was restarted, and the auto start/stop feature was disabled by pressing the "a" inside an orange circle. The contact stated that on another occasion while reversing into the driveway, the vehicle stalled. The message "start engine" was displayed on the screen. The dealer was contacted; however, the vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired and the failure persisted. The manufacturer was not notified of the failure. The failure mileage was approximately 16,000.

Truck started with a knocking noise in the engine that developed into a grinding noise. Dealer service department inspected and did a transmission tear down only to discover the issue is with the excessive play in the crankshaft. At 13k miles, the service department has stated the entire engine needs to be replaced.

I got 3200 miles on my 2025 GMC 1500 6. 2 engine. The engine crash. Knocking. Skund like its going to jump out. Been at dealer in columbus. Since Thursday. No one touch it.

We were traveling when it went into limp mode slowing our speed way down. We got it to a dealership and they determined low oil pressure and metal in the oil. My vehicle only has 1185 miles on it.

Vehicle purchased 8/31/2025 October 20, 2025 "reduced acceleration" alert while driving on why up a significant grade with no way to pull off to the side of the road. Speed limitied to 35mph. Stopped by dealership pulled po6dd code. Appointment made for November 12th. November 12, 2025 routine oil change and service noted "unable to duplicate concern on vehicly, currently no p06dd is present only dtc that was found in history was u1643 lost communications with transmission control module can bus 2. Cleared dtcs and test drove vehicle and is operating normal no issues. Unable to duplicate. " December 4th, 2025 driving on interstate and "reduced acceleration" alert. . . Pulled into nearest dealer and code "p06dd" pulled. December 5th, 2025 returned to home dealership "found code p06dd. As per TSB#25-na-307, checked the crankshaft end play, found the crankshaft has excessive end play. This is an indication of a worn thrust bearing. As per TSB engine replacement is required. " vehicle currently has 6,800 miles.

The engine seized and locked up leading to a catastrophic failure of my three month old 2025 GMC sierra denali at approximately 3,181 miles. The engine, the 6. 2l v8, was listed as a recall engine by gm for model years 2021-2024. My 2025 allegedly "passed inspection" yet had the same catastrophic failure. The vehicle engine made loud noises and it sounded like parts were breaking. The vehicle no longer starts and had to be taken via flatbed to the dealership where I was informed the engine had to be replaced.

- on 9/23/2025 while driving down the main street, the vehicle unexpectedly shut down (engine stopped running) and would not restart. The vehicle is currently at elevation GMC (boone ,nc) waiting to be diagnosed. - safety was put at risk by the vehicle unexpectedly shutting down in the middle the of rush hour traffic and not being able to be moved. - when it is was towed into the dealership and explained to the service manager what happened; she said "there is a known problem with the gear select lever losing communication with the truck and not knowing what gear it is in". - as of 9/24/2025; dealership has not looked diagnosed what the problem is/was. - there were no prior warning messages before the engine shut down.

I purchased a 2025 GMC denali a few months ago. At approximately 7,000 miles, the front brakes failed unexpectedly and were replaced by the dealership. However, by 14,000 miles, I began experiencing brake issues again. Before I could return the vehicle for service, I was driving on the turnpike when the engine suddenly seized without warning. This created an extremely dangerous situation—vehicles behind me nearly collided as I lost power and control. I managed to pull over safely, but the tow truck operator struggled to load the vehicle due to all four wheels locking up and the engine being completely seized. Once the vehicle was inspected at the dealership, I was informed that the engine had failed and would need to be replaced. I am aware of the recurring issues associated with the 6. 2l GMC engines and related component failures, and I no longer feel safe driving this vehicle. Given the repeated mechanical failures and the serious safety risks involved, I am formally requesting that GMC initiate a buyback of this vehicle. I believe this situation qualifies under lemon law protections and warranty obligations, and I urge GMC to take immediate action to resolve this matter.

I’m filing this safety complaint in addition to a previous complaint, 11678151. Which occurred on August 1, 2025. On Friday, August 22, 2025, I experienced a 2nd traction control alert and engine failure lights on my 2026 sierra denali ultimate truck which again caused the acceleration to drastically decline while driving home from work. Thank god my kids were not in the car with me this time.  I am extremely appalled and confused as I've never experienced this level of substandard operation from a new vehicle. I have informed the leadership team team at cavender GMC west san antonio, TX of the situation. The dealerships recommended (2) paths to exit the vehicle: GMC customer assistance and dealership trade-in.

The contact owns a 2025 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle experienced a loss of automotive power. No warning light was illuminated. The vehicle was towed to a local independent mechanic, where it was diagnosed and determined that the engine had seized and needed to be replaced. The local dealer was contacted. The vehicle was not diagnosed or repaired. In addition, the contact related the failure to an unknown recall; however, the VIN was not under recall. The manufacturer was made aware of the failure. The failure mileage was approximately 75,000.

2025 GMC Sierra 1500 has had 2 engine failures since purchase date June 2025. Engine failed on a road trip with my family, leaving me stranded for hours. After the problem being resolved, engine failed once again after 5 months. On the dash it said loss of power and wouldn’t crank to turn on.

I have the 6. 2 l87 with the 10 speed transmission in my 2025 sierra. At cold start, when auto stop restarts the truck, when the truck downshifts under 20 mph down to 12 mph the engine or transmission makes a chirping/squeak/squeal sounds. Several repair attempts have been made, parts replaced. According to gm and their “field engineer” this is a “normal characteristic of the dfm system”. They claim that it has to do with ignition timing. Not my first dfm truck, but it is the first to make this noise. There is not very many components in “the dfm system” that can make a metal on metal squeak/chirp/squeal sound other than lifters/pushrods, but the noise could be coming from the transmission/bell housing area. I am fairly certain this is an early warning sign of engine or transmission failure. Truck currently has 7,800 miles. If this was an actual “normal behavior” for this engine, all of them would make the same noise. But out of 7 other trucks with the same engine and transmission that I have started/drove, none of them made the noise. It has made this noise since I purchased it brand new. A gm field engineer “looked” at the truck 3 weeks ago, and I still have not received any paperwork on what they actually did when diagnosing it. Not a single document from the dealership or gm, regarding the 4 days that my truck was at the dealership on the 4th repair attempt. Gm technical service bulletin I was referred to by the dealership is 22-na-218 will update this complaint when failure occurs.

The contact owns a 2025 GMC Sierra 1500. The contact stated that while at a stop light waiting to make a left turn, the vehicle stalled. The vehicle failed to restart. No warning lights were illuminated prior to the failure. The contact stated that the failure was related to NHTSA campaign number 25v274000 (engine and engine cooling). The vehicle was towed to the local dealer to be diagnosed, and the contact was informed that the engine had seized. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 21,100.

While in the parking lot of a local grocery store, I shifted the vehicle into reverse, at which point all dashboard warning lights immediately illuminated and the braking response became significantly weakened and nearly unresponsive. I placed the vehicle back into park, paused, and then attempted to shift into reverse again, but the dashboard alerts and brake issue persisted. This created a very unsafe driving situation because the brake system was very unresponsive. Despite the unsafe condition, I cautiously drove to my home 2miles away at a speed of under 20 mph, requiring excessive brake pressure to bring the vehicle to a stop. I parked the vehicle in my driveway and left it there overnight. The next morning, I tested the brakes, and they seemed to return to normal so I drove 5 miles to my local GMC service center. Service tech confirmed check engine light on and reported code p0700 and p00ff in the report.

I was driving on a PA road at about 30 mph. My car stopped immediately and I heard the motor rev. The car then slammed into a stop.