GMC Complaints

Transmission has slipped and shuddered multiple times. We have had it diagnosed at gmc dealership and our mechanic, advising that it is 8L90 transmission failure. It will slip to lower gear abruptly, causing for possible safety issues especially on the highways.

I am reporting a serious engine failure in my 2023 GMC Yukon XL (5.3L Ecotec3 V8) at approximately 68,775 miles. The engine began to run rough with a loud chatter noise, and both the check engine light and traction control light activated. Diagnostic tests at the dealer (F.C. Kerbeck GMC) confirmed a P0300 random misfire code and revealed that the lifter on cylinder #5 had collapsed, causing damage to the camshaft lobe. The repair required removing the cylinder head and replacing the lifter, camshaft, pushrods, valves, and associated gaskets and seals. Although I was told this was covered as a ‘goodwill repair’ by GM, I was still charged $3,450 for miscellaneous charges. I find this highly concerning and question whether these charges are consistent with GM’s stated goodwill or warranty policies. In my opinion, a known lifter design flaw requiring such an extensive repair should not result in out-of-pocket costs for the vehicle owner. This failure resulted in a severe misfire and significant performance issues that I believe raise serious safety concerns, including the potential for sudden loss of power while driving. I am submitting this report to NHTSA to ensure this issue is documented and to request that it be included in any broader investigation into GM lifter system failures. Repair invoices are available upon request

The truck in question has LESS than 163k miles and burn a quart of oil a day, loss of power. There HAS been a recall on this SAME MOTOR 5.3 but while this year was ACKNOWLEDGED it was NOT a part of a recall EXCEPT for passenger side air bag that was replaced at dealership and damaged dash in process. Not it is NON DRIVE ABLE due to oil pressure issues

I was in an accident and my AIRBAGS DID NOT DEPLOY. Filed claim with progressive insurance (claim # [XXX]) which they have declared the vehicle a TOTAL LOSS. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

1. On 05/9/25, the exhaust emissions system malfunctioned, triggering diagnostic trouble code P2C7A (exhaust emissions system failure). This repair, the seventh attempt since June 2024, addressed the same recurring emissions issue previously involving replacements of components such as the NOx converter (02/18/25, 03/13/24) and EGR valve (02/18/25). The vehicle is available for inspection upon request. 2. The P2C7A failure risks limp mode, reducing vehicle power unexpectedly, which is hazardous on highways, especially while towing. Exhaust emissions system malfunctions release excessive pollutants, posing environmental and health risks to others. 3. Yes, the P2C7A code was confirmed by dealer during the 05/9/25 repair, following prior confirmations (e.g., 03/31/25–04/05/25. 4. The vehicle was inspected by Young Chevrolet-Cadillac during multiple repairs (e.g., 03/31/25, 05/9/25). 5. Yes, the check engine light and OnStar emissions alerts appeared prior to the 05/9/25 repair, first noted ~June 2024 (P2C7A onset). Exhaust smell and reduced fuel economy were observed intermittently. Symptoms persisted post-03/31/25 repair, leading to the 05/23/25 service.

Subject: Urgent Safety Complaint Dear GMC Customer Service, I hope this message finds you well. I am formally reporting a serious safety issue with my GMC vehicle. The car has experienced multiple dangerous incidents due to likely electrical or software faults, losing power suddenly on two occasions while driving. This is especially concerning given the low mileage of 20,000 km and that the vehicle is still under warranty. Vehicle Information: •Model: GMC Sierra SLE, 2024 •VIN: [XXX] •Current Mileage: 20,000 km Description of the Problem & History: 1.First Incident (At 3,000 km): oThe vehicle completely shut down due to an electrical or system software issue while driving. oThe vehicle was towed to the dealer and held for over two weeks for repairs. 2.Second Incident (Recently): oThe vehicle again lost functionality; the gear was stuck in 1st gear, and I was unable to manually shift. oThis occurred while driving, creating another unsafe situation. oThe vehicle was again taken to the dealer for repair, and to date, I have not been informed of the root cause. Actions Taken: The vehicle was brought to Sarhan, UAE (Sharjah), Al Ghandi Auto after the first incident. Despite inspections and repair attempts, the issue has recurred, indicating it was not resolved. And I am prepared to provide photographic or video evidence if necessary. Additional Context: •The vehicle is less than one year old and has been regularly serviced on time at authorized centers. The recurring issues strongly indicate an underlying reliability or manufacturing defect. Due to the severity and recurrence of these failures, I refuse any further repair attempts. I formally request either a full refund or a replacement vehicle, as this is unacceptable for a new car. Please acknowledge receipt of this complaint promptly and advise on the next steps for a swift resolution. Sincerely, [XXX] Phone: [XXX] Email: [XXX] Location: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2023 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The local dealer was contacted and confirmed that parts were not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

I own a 2023 GMC Yukon Denali XL (VIN: [XXX] ) currently under active recall for the L87 6.2L engine. GM has no remedy available and has acknowledged a risk of complete engine failure and loss of propulsion, which could occur without warning. This is the primary vehicle I have for transporting my family of seven, including a toddler. I am significantly upside down on the loan, and the dealership cannot guarantee it is safe to drive. I am requesting that NHTSA escalate the urgency and hold the manufacturer accountable for timely resolution or replacement.” INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2015 GM GMC Acadia. While the contact's wife was driving at an undisclosed speed, there was a loud sound coming from the vehicle. The contact stated that the service air bag warning light illuminated. The contact's wife stated that a hard piece of plastic had detached out of the dashboard above the radio. The contact stated the failure had occurred twice within minutes. Additionally, the air bag deployed and left a hole in the dashboard. The contact's wife was struck on the head by the plastic piece. The contact's wife did not receive medical attention. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. In addition, the contact stated the GMC database confirmed that the vehicle was repaired under NHTSA Campaign Number: 23V334000 (Air Bags); September 2024, prior to the contact purchasing the vehicle. The manufacturer was not made aware of the failure. The failure mileage was approximately 139,884.

The engine system (6.2L V8 L87) in my 2022 GMC Yukon XL failed due to a known manufacturer defect tied to NHTSA Campaign 25V-274. The vehicle is available for inspection upon request. The issue involves the risk of sudden loss of propulsion, which could result in a crash or injury to myself or others. This is a serious safety concern, and I do not feel safe operating the vehicle in its current condition. The defect has been acknowledged by GMC, but there is no remedy or repair currently available. I have contacted the selling dealership (Rick Hendrick Buick GMC, Duluth, GA) repeatedly for the past three weeks with no returned calls. I also contacted GMC corporate, who confirmed the recall but refused a buyback or replacement because no repair has occurred — even though a fix does not exist. They offered a loyalty voucher that does not come close to addressing the safety risk or impact. The problem has not yet been inspected by a dealer or manufacturer because there is no repair action to take at this time. No police, insurance, or third-party has reviewed the vehicle. There were no warning lights or messages prior to the issue — the problem was revealed when I looked up the VIN and learned of the active recall on the engine. I am requesting NHTSA’s support to ensure General Motors provides a replacement vehicle and compensation for this ongoing and unresolved safety hazard. I should not be placed in a position where I am expected to continue operating a vehicle with a known and dangerous defect that has no resolution in place.