GMC Complaints

LT275/65R20 is tire size. On 26 August 2025 the tread separated from the left front tire completely, but the tire did not go flat. Traveling in Texas near Christoval, TX at 75 mph on smooth roads. The vehicle had 26,000+ miles and tread depth was over 4/32nd. Front tires were replaced. On 21 October 2025 the tread separated from the left rear tire 90 percent of circumference and the tire ripped open. Vehicle had 27,600+ miles on it. Traveling near McLoud, OK on Hwy 102? at about 50 mph on smooth road. Rear two tires replaced on 23 October. These two tires are in my possession for inspection, tread depth was 4/32nd and 5/32nd. Claims have been submitted to insurance. Picture of 2nd incident attached. These two incidents indicate to me that these tires are defective and should be recalled. Failure has been verified by GMC dealer and Walmart. There were no warning lights either time.

My vehicle is equipped with multiple safety systems offered by general motors. Since purchasing my vehicle new, I have had a persistent and recurring issue related to the vehicle safety system, which is resulted in numerous collision detection and advanced cruise control service is not functioning as designed, creating safety issues for both myself and potentially other motorist on the road. Additionally, the parking sensors are not working as expected, presumably due to the same issue, which has resulted in numerous safety concerns, including the detection of vehicles or objects, which were not present, resulting in the systematic breaking function engaging posing a risk to myself and surrounding motorists. I initially reported the issue to GM on 2/20/2025, when the vehicle had 467 miles on the odometer. Since the issue initially began, I have returned to the GM service department at my local dealer a total of seven (7) times. The local service department has been in contact with GM corporate office related to the issue, however, they have been unable to rectify the issue and continue to send the vehicle back out on the road claiming the issue has been resolved only for it to recur shortly thereafter. I believe that GM providing the safety features in an inoperable state poses great risk to the general public, and the NHTSA should investigate this issue alongside the other active systemic issues GM is currently under investigation of. At this time, it is unknown what is the cause of the issue, multiple parts have been replaced, and the true cause of the issue has been undiagnosed.

Tick sound coming from underneath. Also fumes smell. Dealership found it to be the exhaust system. Said the muffler valve is bad. Quoted me $2000 for repair. Never heard of a exhaust system failure in only 5 years. Very unsatisfied with this.

Vehicle Information Make: GMC Model: Yukon XL Denali Year: 2021 VIN: [XXX] 1. What component or system failed or malfunctioned, and is it available for inspection upon request? The engine failed due to defective lifters and camshaft components, along with excessive oil consumption. These issues rendered the vehicle inoperable and required over $10,000 in repairs. The failed components are available for inspection upon request. 2. How was your safety or the safety of others put at risk? The engine failure occurred while the vehicle was in motion, creating a dangerous situation for my family and other drivers. Sudden loss of engine power could have led to a collision or left us stranded in unsafe conditions. 3. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. The issue was diagnosed and confirmed by DeFouw GMC in Lafayette, Indiana. GMC has acknowledged the defect and agreed to cover all but $2,000 of the repair costs. 4. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? The vehicle has been inspected by DeFouw GMC. GMC is aware of the issue under Case #[XXX]. No inspections have been conducted by police or insurance representatives. 5. Were there any warning lamps, messages, or other symptoms of the problem prior to the failure, and when did they first appear? No, it all happened at once. The vehicle was extremely well cared for, and GM has all of the oil change records. Additional Comments: We have been without our family vehicle since [XXX], and GMC has not provided an estimated arrival date for the replacement engine. We are now entering month four without a vehicle, which has severely impacted our family’s mobility and safety. This delay is unacceptable and reflects poorly on GMC’s commitment to customer safety and service. Has also cost us over $10,000 out of pocket, which I will seek reimbursement for legally, if I must. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U

SuperCruise Repeatedly crosses Double yellow lines even with on coming traffic. Sometimes with SC active it will make an auto lane change but halfway through it will randomly swerve into either lane, or just simply turn off without warning. It started happening after a software update in May of 2025. We have provided GM and the dealership with Video evidence, along with the dealership mechanic replicating the problems. GM states that SC is operating as intended and that we are not to bring the truck in for service for that issue again. they denied buy back twice now.

I have the little feature that will brake for me if it thinks ima get in a wreck. However it’s glitchy!! I can be the only vehicle on road in BOTH directions, cruise set at 60 when out of nowhere the car slams on the breaks. We go down to like 52 then like nothing ever happened we are back to 60. This has happened several times. I have brought the car into my dealership tomorrow have the software updated and the camera recalibrated. Even after these steps were made this issue is still occurring. Happens about one to two times a week, so pretty often. My worries that I will be rear ended one day if this is not corrected.

On [XXX], at approximately 15,873 miles and while on the freeway approximately 30 miles from my home, my GMC Sierra 1500 with the L84 engine experienced a failure of the DFM lifter assembly. This required a significant engine disassembly and the replacement of multiple valvetrain components. This repair was performed at Gold Rush Chevrolet in Auburn, CA, as documented in the enclosed service invoice. GM has issued Technical Service Bulletins and product communications addressing similar lifter failures in Gen V small-block V8 engines with DFM/AFM, including Service Update N212353840, PIP5776, #19-NA-219, and related updates. Industry coverage and owner reports and current Class Action Lawsuits indicate that these failures can recur, even after initial repairs, due to the high cycling frequency of the DFM lifters. Given the nature of the defect and GM’s documented acknowledgement of the issue, I am requesting that GM extend the powertrain warranty coverage for the engine and related valvetrain components for a period of 10 years,100,000 miles as a goodwill policy adjustment. A warranty extension would ensure customer confidence and protect against the significant cost of a repeat failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2018 GMC Acadia. The contact stated that while the vehicle was parked and occupied, the shift to park message was displayed while the vehicle was in park. Neither an independent mechanic nor the dealer was contacted. The vehicle was not taken to an independent mechanic or dealer for diagnostic testing. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number:17V516000 (POWER TRAIN); however, the VIN was not included in the recall. The manufacturer was notified of the failure and informed the contact that the VIN was not included in the recall. The failure mileage was 113,000.

Brake sensor warning pops up that says brake pads need to be serviced. Brake pads still have between 80-92% wear left according to the dealership. There is a TSB out for this issue (#N242471431) but GMC refuses to repair at no cost. States that even though my vehicle is within the parameters of the TSB, it is VIN specific.

Molding between top of grill and hood came off while traveling on highway and struck windshield and broke it.