Power Train Problems of GMC Sierra 1500 - part 2

While entering the freeway at approximately 45 mph not towing the rear wheels locked for a second, truck went into the limp mood, and dash said reduce speed, service transmission. Dealer pulled codes, p0700 and p0747. . . The order says cause document #6998510. "replace spacer plate, check balls and valve. " correction: dtc p0747 set dealer told me the put the new updated valve in but I don't see that on the repair order? I asked about the gm extended warranty ( I think it's 10 years, 150,000 miles). They said it didn't apply to my vehicle?.

See all problems of the 2023 GMC Sierra 1500 🔎.

The def tank in my truck is defective and its the second time in the last 14 months it has broke. The part is now back ordered and according to the dealership this is a nationwide issue regarding these specific trucks. I have contacted around 10 dealers in my area and all tell me the same thing that they have multiple trucks waiting on the same issue. I have not had my truck for over 2 months and have no idea when I will be getting it back due to dealership having no idea when the part will be released due to the back order. This seems to a huge issue with these trucks and gm is doing nothing to help resolve it. I've reached out to gm directly and get no assistance and now have made 2 payments on my truck and the dealership refuses to give me a loaner vehicle. I am looking for some help or relief on what to do to go about my issue.

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Vehicle: 2023 GMC [model], black widow package, 6. 2l l87, 41,078 miles recall: 25v?274 / gm [xxx] ; recall remedy performed by marty’s GMC (kingston, MA) on 2025 -11-12; oil changed per recall procedure post?remedy symptom: intermittent knock starting ~01 - 2025 / about two months after remedy incident: Jan 23, 2026 — engine seized / loss of propulsion while driving; stranded on highway off?ramp; vehicle impeding traffic causing dangerous conditions. Codes: obd scan by passerby indicated camshaft position sensor / correlation error (exact code not captured) crash/injuries: none current status: vehicle at marty’s GMC since Jan 23; not diagnosed as of Jan 29; GMC case #88159466 safety concern: sudden loss of motor power in traffic after recall remedy on Friday, Jan 23, 2026, while my daughter was driving, the engine seized / the vehicle lost propulsion and stranded her on a highway off?ramp. The vehicle was impeding traffic and had to be moved. It restarted briefly and was moved to a safer location but still impeding traffic. A motorist scanned the obd port and reported a camshaft position sensor / cam-crank correlation error (exact dtc unknown). No crash occurred and no injuries occurred. The vehicle has been at marty’s GMC since Jan 23, 2026 and as of Jan 29, 2026 it has not yet been diagnosed. I opened a case with GMC customer assistance (case #xxx). This is a safety-related loss-of-propulsion event occurring after the recall remedy was completed. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The contact owns a 2015 GMC Sierra 1500. The contact stated that while at a complete stop and attempting to shift into reverse(r), drive(d) or park(p), the gear shifter was stuck, and the contact had to go underneath the vehicle to move the shifter cable into the intended gear. The vehicle was taken to an independent mechanic, where the upper and lower shifter cables were replaced. The contact stated that upon returning to the residence and attempting to park the vehicle, the gear shifter failed to remain in the intended gear and was moving unintendedly. The vehicle was not repaired. The dealer and the manufacturer were not contacted. The failure mileage was approximately 225,740.

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On the afternoon of 01/20/26, I was merging onto the highway in my 2021 GMC Sierra 1500 when a loud bang was heard from the engine compartment at approximately 60 mph. Immediately after the ban was heard, several indicator lights on the dashboard were illuminated, including the esc, check engine light, and parking brake light. A power loss was felt when attempting to accelerate and the banging noise worsened anytime the accelerator was depressed. I was able to drive the vehicle to the nearest gm dealership that coincidentally was at the closest exit off of the highway I was traveling on. The dealership performed diagnostic and determined that the damage was caused due to the ongoing gm recall associated with safety recall n252494000. My vehicle had previously been inspected as part of the recall and was found to have passed. Vehicle had been driven approximately 4,000 miles after recall was performed.

4 months after bring my truck back to the dealership for a body valve issue on the 10 speed transmission. The truck went into limp mode while I was driving.

Driving at 35 mph in traffic and the rpms started to increase to 3500rpm and vehicle started to slow down inevitably putting me into reduced acceleration. . Limp mode. Truck would not shift into reverse either once I could safely merge out of traffic and put into park. Very very dangerous and scary situation.

I had the truck inspected for recall n25249400 on August 11, 2025 with 24,610 miles. It passed the recall inspection and the dealer changed the oil to gm recall recommended oil. On January 18, 2026 with 28,275 miles, the engine seized while on a major highway. The truck lost all power and just turned off amd would not start or turn over. The vehicle was towed by the police due to the vehicle being in a dangerous spot in the middle of a lane on the highway whi h I had to pay out of pocket. January 19, 2026, the gm dealer confirmed that the truck needs a new engine due to the recall defect. They said that they had just ordered a new engine, but does olnot know hpw long ot will take to get and then install. The dealer is unable to provide a rental vehicle which means, I can't work!.

While traveling 60 mph on a divided highway went to pass another vehicle. Had no throttle response the engine had completely turned off, locked up seized up. I’m not sure what caused the engine to just lose all power. Had to go back to the lane and luckily there was a turnoff where I was able to turn off the highway.

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While traveling on a major route, the truck just turned off while driving. The truck was stuck in the middle of a two lane major route. Truck would not start or turn on. I was unable to put hazards on or put the truck in neutral. The engine siezed due to the gm recall. After having the engine replaced by a certified gm dealership, a few days later the throttle body stopped working. Again, keeping me stuck. Certified gm dealership had to replace the throttle body.

To start off my truck has been to the dealership multiple time for the camera. After third time in the shop they fixed that issue. Then the infotainment started acting up after about 4 times in the shop it was fixed. They gave me the prescribed fix for the engine recall in November. Engine passed the test. Then 3 weeks ago the engine siezed up from the crank and bearings on the interstate doing 70 pulling a trailer in traffic. Leaveing me and my dad in the middle of the interstate. I had to have it towed 2 hours to my house. After the prescribed engine fix. They replaced the motor in 3 days. Great right? no they did not test drive long enough. Or they would have felt the shudder that developed after the new engine went in. It is now about to go back to the shop. Because of the shudder at low rpm and im haveing electrical issues again as well . My remote start also stopped working after the engine replacement.

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The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at various speeds, there was an abnormal vibration in the steering wheel. There was no warning light illuminated. The contact stated that the tires were replaced, and the wheels and bearings were inspected by an independent mechanic, but no failure was found. The independent mechanic related the failure to an undisclosed transmission recall; however, the dealer informed the contact that the VIN was not under recall. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was approximately 28,000.

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Vehicle passed initial inspection and had higher viscosity oil installed. After driving for the past six months I noticed a burning oil smell inside the truck. The smell gets intense at times especially during highway driving. The ow-40 viscosity oil is causing high fumes within the cockpit. Please consider checking this issue out during your added investigation into the l-87 engine failure. I shouldn't have to drive with the windows down but I do. I will have the truck inspected during my next oil change next week.

The oil cooler line is leaking, and the vehicle is available for inspection upon request. This safety concern is addressed under gm program n192220080. The hazard is present: the leak is active. The risk of total line detachment and engine seizure is the same in texas as it is in alaska (the us state the GMC recalled the exact same part). An engine seizure and loss of propulsion is an immediate danger to passengers within the effected vehicle, as well as the other vehicles on the road. The admission of defect: gm’s offer to provide the part (part #85136335) confirms that my vehicle’s hardware is part of the failed batch. The vehicle was inspected by an authorized GMC dealership on 01/14/2026, confirming the leak and potential safety hazard with continued driving of the vehicle. The issue was submitted to the gm customer care team, case #[xxx]. The only warning of the defective oil cooler line leak was oil on the ground underneath the vehicle after driving. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

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Vehicle was in neutral on an alignment rack with no one in the vehicle. Vehicle was idling. Vehicle shifted into reverse on its own (no one in the vehicle) and backed off the alignment rack causing $7,000 estimated damage to the vehicle. This happened at a tire dealership (tgk, owatonna, mn). Luckily no one got injured or killed. No inspection yet. No warning messages. This truck has had numerous "electrical glitches" previously that have had no resolution. This "glitches" have included loss of power while driving, 3 times smelling like burnt wiring upon start up, left mirror motor going bad, right mirror motor going bad.

I am an owner of the same year, and model GMC Sierra 1500 included in the gm customer satisfaction program n212326940, which is the oil cooler line failure. However, my VIN was not included in the program despite experiencing the exact same failure the program covers. My safety and the safety of others is put at risk because the failure may cause an immediate loss of oil pressure or propulsion while driving. This is a huge safety hazard, since loss of vehicle control may occur. My vehicle has been inspected by a certified gm dealer and they confirmed the oil cooler line has failed and must be replaced. I have not experienced any warning lights, but my vehicle is leaking an excessive amount of oil. The vehicle is no longer safe to drive until repaired.

1-at approximately 40,000 miles, my transmission was replaced under warranty. It had been failing since approximately 2000 miles having a very hard time shifting between first and second gear. It was finally replaced at 40,000 miles. 2- at approximately 45,000 miles I took my truck into the dealership for this latest recall on the 6. 2 l failure for inspection. Vehicle is inspected and I was told I would need to have an engine replacement. I was told that there was no eta on when a replacement engine would be available and that I would be contacted when one was. Afterwards I was sent back home in the truck they just inspected for potential engine failure and said had a bad engine. As of now, I’m still waiting on a word of a new engine and my truck is still operating, but leaves me concerned that it could fail at any moment while driving it.

The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle was shaking abnormally. No warning light was illuminated. The vehicle was taken to the dealer to be diagnosed, and it was determined that the engine needed to be replaced. The vehicle was then taken to an independent mechanic, who determined that the torque converter had failed. The torque converter was replaced, but the failure persisted. The vehicle was taken back to the independent mechanic, who replaced the torque converter a second time. The manufacturer was not made aware of the failure. The failure mileage was approximately 140,000.

26’ GMC Sierra 1500 at4 3. 0l duramax experiencing harsh shifting occurring sporadically while accelerating and deceleration. More frequent and severe during quick deceleration. Severe clunking/rear wheel lock up while reversing. Very repeatable. Truck was a dealer demo and had 2400 miles on it when I bought it last week. Took it in to the dealer today and they said I need a complete new transmission.

On Wednesday, January 7th, 2026, my wife and I were traveling north on the northeast extension of the pennsylvania turnpike (476) at approximately 9:00 pm. A check engine light came on with no other symptoms, we start to get off the next exit. While still on the highway, the motor turns off with a warning to put it in neutral and restart. It would not restart and coasted off the exit and into a convenience store parking lot. There was noise, just turned off. We got stuck in the town for over 2 days before getting a tow 209 miles to the mechanic shop. We were miles from any mechanic shop and tried to troubleshoot while waiting and to no avail. First mechanic had to send it to a second because it looked like the engine had seized and that was confirmed at the second mechanic shop. Apparently the bearings in the lower end seized. The only thing they could offer was to replace the motor. It had proper amounts of fluids and didn't overheat. The motor replacement is approximately $10,800. 00 in addition to having no vehicle there was additional towing and breakdown expenses (food and lodging for 2 nights and 3 days).

While traveling down the highway at approximately 60-65mph I pressed the accelerator to change lanes and pass a tractor trailer when it felt like my transmission slipped very abruptly. There was a very noticeable power loss and the truck would not accelerate. Then I noticed a loud knocking noise coming from the engine. No check engine light or any other indications on the dash to let me know there was a problem. I began to try and merge to the right of the highway to get off which was not easy do to the power loss and heavy traffic on the highway at the time. I made it to the right lane to exit the highway and when I slowed down the engine died and I had to coast to a stop luckily on an exit ramp. The truck was towed to a dealership and they state that I will need a new engine. I know this issue is already well documented with the gm 6. 2l engines but I is very unsettling that the engine just died on the highway at highway speeds and no indications.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while his wife was driving at an undisclosed speed, the vehicle jerked violently. The driver stated that the vehicle failed to respond as intended while depressing the accelerator or brake pedal. The check engine warning light was illuminated. The driver was able to pull over to the side of the road. The vehicle stopped jerking while driving but failed to exceed 30 mph. The driver pulled into a parking lot and parked the vehicle. The contact was made aware of the failure and went to the parking lot. The vehicle was restarted and jerked abnormally. Additionally, while shifted into reverse(r), the vehicle failed to function as intended. The vehicle was taken to the dealer, where it was diagnosed, and two dtc were retrieved for unknown transmission software failure, and it was determined an unknown part in the transmission had failed. The dealer informed the contact that an unstated recall was closed. The vehicle remained at the dealer unrepaired. The manufacturer was made aware of the failure, a claim was filed, and the contact was informed that the recall was closed. The failure mileage was approximately 146,000.

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I was driving my vehicle on the highway when the transmission suddenly gave out with no warning whatsoever. When I say gave out, I mean, it just completely stopped working and was unable to go into any gear. I was luckily able to coast over to the median without an accident occurring, but it was not without much concern or worry as traffic moving on the highway is 70 miles an hour plus and quite full of vehicles . I consider myself lucky that I have extensive driving experience and was able to conduct myself calmly under the circumstances. It was a bit tricky, getting situated though under those circumstances. There was no advanced warning in anyway. No engine lights, no sounds ,nothing. This is a well maintained vehicle. All my service is done by the dealership, and I have never been given any indication that there was something wrong. However,after this happened, I have been researching and found that many of these vehicles with this transmission continue to have this problem. This is not normal wear and tear or normal mechanical failure. I have owned many vehicles and never felt as unsafe as I did in that moment, or had a vehicles transmission fail so abruptly. For me, and the research I have done, I can only hypothesize the materials and engineering involved with this transmission are inherently inferior, completely faulty, and a safety risk/hazard to anyone who owns or operates the vehicle. I consider myself lucky to walk away unscathed, other than the economic price that it is going to incur on my finances for repairs. I would hope that it doesn’t take something serious to happen before someone takes action and conducts a recall of this product. From what I have read and what I have experienced, this is truly an unfortunate accident waiting to happen and it appears nothing is being done. I truly hope that you could take a little more look into this matter. Thank you for your time and energy. I have already contacted the manufacturer and felt ignored.

Driving down the road and engine shut off and would not start back. Had it towed to dealer and it needed a motor replacement. Waited over a month for the shop to finish it. New motor has 3k miles on it and is making noise, transmission is stuttering hard and the air conditioning quit working all around the same time. Had to take the truck back to the dealer after the replacement motor was installed because of a faulty “new” starter.

My engine is projecting a ticking sound. Oil consumption is extreme.

I believe the torque converter is failing. While driving approximately 38 mph and also 48 mph up to 51 mph the vehicle have a vibration feeling like driving on a rumble strip. If you maintain the same speed, the vibration continues if you speed up, slow down, or let off the gas it goes away. There are so many detailed explanations on forums and social media from other customers experiencing the same problem, but not seeing any recall made by GMC.

Tranmission is shuttering and not wanting to shift right.

My tailgate kept opening randomly and engine was making clunking sound initially. Lost many tools on the highway once when it opened. Dealership told me my truck is not covered under a recall for both issues, even though other similar vehicles are. I refused to pay anything to have it fixed. They claimed my truck “wasn’t built in the factory that has recalls”. A month later the starter and battery burned up when I started up the truck, something locked up it sounded like. Eventually it started but didn’t sound right. A few days later the engine finally blew up. I paid out of pocket for everything for that trip. It’s currently back at the dealer being repaired with a new engine for the recall but GMC refuses to pay for the initial clunking/starter/battery and the tailgate issues. I’ve encored so many charges with tows and rentals from all these issues. I would like full reimbursement for everything.

I live in illinois, my 2019 GMC Sierra 1500 slt has 51,318 miles on it as of 12/31/2025. What component or system failed or malfunctioned, and is it available for inspection upon request? engine oil cooler hose line detaching from crimp - small oil leak currently. Not yet fixed. Available for inspection. How was your safety or the safety of others put at risk? if this component fails, all oil from the vehicle will be lost and inoperable. This could cause a traffic accident, especially if towing a load. Has the problem been reproduced or confirmed by a dealer or independent service center? confirmed by an independent service center. I will be taking my vehicle to the local GMC service center for additional confirmations. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? no, but gm has acknowledged the issue through these customer satisfaction surveys (csp xxx/ xxx). Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? there has been no failure yet. A small oil leak was found on my garage floor. My issue is that this is a known issue in cold weather climates. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

70mph with cruise control on, truck shifted from drive to neutral uncomanded. There were no indications of the issue before it happened. The dealer has the truck and I havent heard back from them yet. From my limited research, this is a common problem for these trucks.

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.

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).

See all problems of the 2025 GMC Sierra 1500 🔎.

Driving home with kids from snowboarding and check engine light comes on. “power reduced, drive carefully” well I’m in 4 wheel drive the roads aren’t great and I have my kids in the truck. We were safe. Now? I am nearly getting ran off the road there aren’t any exits from the freeway. Kids are terrified. Able to limp home all the while with crying kids. Hook up scanner and it’s p1098. A little research tells me it’s a coolant control valve. Which is known problem from GMC so much so that the company issued an extended warranty to cover. No recall? no just let people experience this event across the country in a truck that is billed as safe and reliable by the company that sells them. This is a complete joke. The part is on national backorder because the problem is so prevalent. So now I have a truck that is inoperable. 52k miles and it’s a 2022. Someone needs to investigate this company as soon as possible.

Bought truck 0n 12/26/2025 from lot in michigan had it transported to missouri. First time I drive it check engine comes on and goes into "limp mode". Had it towed to gm dealer and they say it was the high pressure fuel pump. Got it back and check engine light comes back on then goes off then back on again. Not happy at all!!!.

I had a lifter fail which is a well known problem for these gm engines. The lifter caused the cam shaft to be damaged because of the lobes being shaved off. Now I’m being told that it will be over $10,000 fix a 3 year old truck.