GMC Sierra Complaints (2026)
171 consumer complaints on file.
- #11737988May 15, 2026ENGINE, FUEL/PROPULSION SYSTEM, STEERING
I recently purchased my vehicle from Big Star Dealership in Baytown Tx. At a little over 1000 miles i was towing a camper. The vehicle stalled, fuel pouring from engine. It was towed and repaired due to fuel pump failure. At a little over 3000 miles the vehicle would not start. Dealership initially said water contamination then changed it and said gasoline contamination and now they say DEF contamination. The vehicle stalling the first time almost caused me to wreck the vehicle
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11738215May 15, 2026POWER TRAIN
Transmission Cooler line blew out
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11737424May 12, 2026ENGINE
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.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11737046May 11, 2026STRUCTURE:BODY
The tailgate intermittently opens while driving or parked
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11736788May 9, 2026ENGINE
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!
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11736469May 8, 2026ELECTRICAL SYSTEM
During normal use, the factory wireless phone charging pad in the center console overheated, produced visible smoke inside the cabin, and melted the charging surface area. No liquids or foreign metal objects were present. The phone was placed normally on the charging pad. The incident created a burning smell and visible damage to the interior trim. The system did not shut down before damage occurred. This appears to be a potential electrical or thermal safety failure in the factory-installed wireless charging system.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11735797May 5, 2026ENGINE
6.2 ENGINE BLEW UP 3000 MILES
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11734694April 29, 2026STEERING, SERVICE BRAKES
Brand new delivery there was a noise that changes with engine RPM. It also changed with turning the steering wheel. The dealer diagnosed a bad power steering pump. Due to possible metallic contamination all related parts that are connected to the power steering pump including the HydroBoost brake assist are going to be replaced
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11732292April 20, 2026POWER TRAIN, ENGINE
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.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11731366April 15, 2026UNKNOWN OR OTHER, FORWARD COLLISION AVOIDANCE: WARNINGS, LANE DEPARTURE: ASSIST
Vehicle keeps displaying a warning message to service drivers assistance system. Taken the vehicle to the dealership multiple time and the condition still persists. Dealership contacts GM tech support and are being told that GM is aware of the problem, programing issue, but they have no solution after several months. Multiple vehicles at many dealerships have the same problem. I don't feel safe driving the vehicle. Drivers assistance system includes multiple cameras and sensors. This condition could cause severe accidents of even death if the system gives false or wrong information
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11730419April 10, 2026ENGINE, POWER TRAIN
ENGINE LOCK UP WITH 5018 MILES ON, IT IS A THE 6.2 MOTOR ROD AND CRANK BAD
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11730473April 10, 2026ENGINE
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
- Injuries:
- 0
- Deaths:
- 0
- #11729792April 7, 2026ENGINE
Complete engine failure at 1838 miles. Need complete engine replacement. Estimated time unknown for replacement parts.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11729257April 5, 2026ENGINE
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
- Injuries:
- 0
- Deaths:
- 0
- #11729317April 5, 2026POWER TRAIN, ENGINE
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
- Injuries:
- 0
- Deaths:
- 0
- #11727173March 26, 2026ENGINE
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
- Injuries:
- 0
- Deaths:
- 0
- #11727195March 26, 2026ELECTRICAL SYSTEM
Radio has zero sound - the issue is the radio sound also has the blinker sound, hands free safety/navigation guidance along with the On Star safety function. None of that is functional. The dealer states it's a known issue and parts are not available. How can this be when they keep building new units. GM has been contacted with zero help and no response around my safety concerns. While it seems like a small thing when we say radio I'm not concerned with the lack of music but this system controls way more than music.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11726720March 24, 2026ENGINE
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
- Injuries:
- 0
- Deaths:
- 0
- #11726573March 23, 2026ENGINE
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
- Injuries:
- 0
- Deaths:
- 0
- #11726026March 21, 2026SERVICE BRAKES, POWER TRAIN, FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
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
- Injuries:
- 0
- Deaths:
- 0