Complaint volume
60 consumer-submitted complaints are matched to this model year. Treat the count as a research signal, then read the actual summaries for repeated symptoms.
Complaint records
60 consumer-submitted complaints on record for the 2026 GMC Sierra, grouped by component category.
Buyer interpretation
Complaint records are most useful when they turn into inspection points, seller questions, and comparison checks against nearby model years.
60 consumer-submitted complaints are matched to this model year. Treat the count as a research signal, then read the actual summaries for repeated symptoms.
The most common categories are engine, power train, forward collision avoidance: warnings. Use those categories as a test-drive checklist instead of judging the vehicle from the total count alone.
The enriched records we matched do not show crash, fire, injury, or fatality flags. Still check complaint summaries for repeated drivability, braking, electrical, or visibility symptoms.
Mileage is available on 4 complaints, with an average reported failure mileage of 5,330 miles. Compare that with the mileage on the listing.
Build a buyer checklist to turn these issues into questions and inspection points.
60 total complaints on record
| Date | Component | Summary | Severity | Mileage |
|---|---|---|---|---|
| Apr 2026 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| Apr 2026 | POWER TRAIN | ENGINE LOCK UP WITH 5018 MILES ON, IT IS A THE 6.2 MOTOR ROD AND CRANK BAD | Crash: No Fire: No | Unknown |
| Apr 2026 | ENGINE | Complete engine failure at 1838 miles. Need complete engine replacement. Estimated time unknown for replacement parts. | Crash: No Fire: No | Unknown |
| Apr 2026 | POWER TRAIN | 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. | Crash: No Fire: No | Unknown |
| Apr 2026 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| Mar 2026 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| Mar 2026 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| Mar 2026 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| Mar 2026 | SERVICE BRAKES | While driving at approximately 60 mph on an open road with no obstacles present and no braking input, the rear wheels spontaneously locked up without warning. No brake pedal input. No warning light prior to the event. No obstruction in the road. The vehicle has been subject to an active manufacturer recall for rear wheel lockup due to transmission control valve failure. The dealer's own diagnostic system generated a report showing six active fault codes in the following days including lost communication with the Brake System Control Module and Transmission Control Module. These codes were not addressed on the repair order. The dealer attributed the lockup to an Automatic Emergency Braking activation without diagnostic confirmation and performed no repair. The manufacturer's own internal bulletin dated January 22, 2026 acknowledges the exact fault codes present on this vehicle as a known defect. The dealer cited this bulletin to dismiss the concern while stating no problems exist. A persistent brake noise has been confirmed by two separate authorized dealers across three visits with no repair performed at any visit. The vehicle has required five dealer visits in 77 days of ownership with 1,729 miles. The defect remains unresolved and poses serious risk of loss of vehicle control at highway speed. | Crash: No Fire: No | Unknown |
| Mar 2026 | STEERING,ELECTRICAL SYSTEM,UNKNOWN OR OTHER | I had this truck as brand new for approximately 24 hours when it had a major failure. It had 450 miles on it at time of purchase, but was sold as new. While driving at 45MPH it had a check engine light, service power steering message, lost power steering, lane departure system failure, and reduced power amongst several other lights on the dash. I limped the truck into a gas station parking lot. After turning the truck off, it would not restart. I unhooked the battery for a minute and hooked it back up. The truck did restart with no messages or check engine light. I was able to safely get it to the dealership. As a result of this issue, I forced the dealership to cancel the trade. | Crash: No Fire: No | Unknown |
| Mar 2026 | FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING | 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) | Crash: No Fire: No | Unknown |
| Mar 2026 | SERVICE BRAKES | I was out one day for lunch and my brakes stopped working on my truck. I had the truck towed after I limped home in it. The master cylinder failed at 4,200 miles causing the brakes to fail. It was replaced by the dealership. | Crash: No Fire: No | Unknown |
| Mar 2026 | POWER TRAIN,VEHICLE SPEED CONTROL,ENGINE | My engine seized up on me on the highway. I was stranded and couldn’t start the vehicle and it was freezing outside. | Crash: No Fire: No | Unknown |
| Feb 2026 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| Feb 2026 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| Feb 2026 | EQUIPMENT | The contact owns a 2026 GMC Sierra 1500. The contact stated that after purchasing the vehicle, there was no Owner’s Manual in the vehicle. The contact inquired about the Owner’s Manual and was informed by the dealer that an Owner’s Manual was no longer printed. The contact checked online and became aware of FMVSS 225, which was related to the Owner’s Manuals for similar vehicles. The contact researched NHTSA Campaign Number: 25V815000 (Equipment), addressing the lack of an Owner’s Manual for 2026 Chevrolet Silverado 1500, 2500, and 3500 vehicles. The manufacturer was not notified of the issue. | Crash: No Fire: No | Unknown |
| Feb 2026 | ENGINE,FUEL/PROPULSION SYSTEM | "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 | Crash: No Fire: No | Unknown |
| Feb 2026 | POWER TRAIN,ELECTRICAL SYSTEM,ENGINE | 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. | Crash: No Fire: No | Unknown |
| Feb 2026 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| Feb 2026 | POWER TRAIN | My 2026 GMC AT4 3.0L Duramax had a catastrophic engine failure on Sunday, February 8, 2026. It went into reduced acceleration and also fault code PO6DD. Thankfully I was not on a highway. The truck would not run over 45 MPH on flat ground, and then by the time I got it to a safe location 5 miles away it would not run over about 30MPH. This obviously resulted in the truck being towed to a dealership. I have been told the entire engine will be replaced. Upon further reading, I suspect this is a thrust bearing failure that is a well-known issue in this LZ0 Duramax engine. What I have read, this issue is occurring mostly on trucks built from May-Sept 2025, and my truck has a 7/2025 build date. This could have been major safety hazard if the engine had failed in a major freeway/highway. | Crash: No Fire: No | Unknown |
| Feb 2026 | POWER TRAIN | I am submitting this complaint regarding a recurring transmission issue in my vehicle. The transmission consistently jerks and shifts erratically, particularly in the morning during initial operation when at cruising speeds of about 50-75 mph. This behavior occurs when the transmission temperature is below approximately 100°F and happens on a daily basis. The gear changes feel harsh and abrupt, kind of like it doesn’t know what gear to be in its raising concerns about both drivability and long-term transmission reliability. I brought the vehicle to an authorized dealership for inspection. After evaluating the issue, the dealer informed me that the behavior was due to the vehicle being in “Sport Mode.” However, this explanation does not resolve the concern, as the severity and consistency of the jerking appear abnormal and occur regularly under the same temperature conditions. Given the persistent nature of this problem and its potential safety implications — especially during acceleration and low-speed driving — I am requesting that this issue be formally documented and investigated. Thank you for your attention to this matter. | Crash: No Fire: No | Unknown |
| Feb 2026 | ENGINE | 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. | Crash: No Fire: No | 6,000 |
| Feb 2026 | ENGINE | "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." | Crash: No Fire: No | Unknown |
| Jan 2026 | ENGINE | 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 | Crash: No Fire: No | Unknown |
| Jan 2026 | FORWARD COLLISION AVOIDANCE,LANE DEPARTURE | GMC SUPER CRUISE MALFUNCTION NO WARNING BEFORE SUPERCRUISE SHUTS OFF PASSING A CAR ON FOUR LANE HIGHWAY (SUPER CRUISE ENABLED) SUPER CRUISE SHUT OFF AND TRUCK CONTINUED HEADING FOR THE CENTER GAURD RAIL.(I CAUGHT IT BEFORE IT BECAME AN INCIDENT). SUPER CRUISE ABRUPTLY SHUTS OFF (NO WARNING) AND WITHIN A COUPLE THOUSAND FEET IT TURNS ON. MY FIRST TIME USING SUPERCRUISE AZ HIGHWAY 87 N BOUND JUST BEFORE RYE AND AZ HIGHWAY 260 BETWEEN PAYSON AND CHRISTOPHER CREEK I CALLED MY DEALERSHIP BUT IT WAS LIKE UH HUH OK I'LL LET GM KNOW.- NO SUPPORT! THE ONLY INDICATOR IS ON THE STEERING WHEEL A RED,GREEN OR YELLOW LIGHT.RED IS OFF-GREEN IS ACTIVE, AND YELLOW LIGHT NO SERVICE. RED LIGHT COMES ON AND SEAT VIBRATES SUPERCRUISE DROPS OUT. | Crash: No Fire: No | Unknown |