My vehicle had a previous engine recall that was “fixed” per the dealership recommendations. However, I succumbed to total engine failure last week at 70000 miles with my 2 little kids in the car on an interstate. My engine needs replaced.
No injuries · No fire · No crash
I am reporting a severe, recurring, and life-threatening manufacturing defect involving a sudden, catastrophic loss of motive power at highway speeds on the interstate. This vehicle has suffered two identical valvetrain failures that placed my passengers and nearby motorists in extreme danger. Incident 1 (Approx. 40,000 miles): While traveling at high speed on the interstate, the vehicle violently shook, all engine warning lights flashed, and the engine suffered an immediate, near-total loss of propulsion. The vehicle was towed to an authorized GMC dealership, where technicians diagnosed a collapsed Dynamic Fuel Management (DFM) hydraulic lifter in Cylinder 3. The lifter bank was replaced under the factory powertrain warranty. Incident 2 (Approx. 77,000 miles): While driving at high speed on the interstate, the exact same vehicle behavior occurred. The engine suffered a sudden, total loss of power, and all dashboard warning lights illuminated simultaneously. Out of absolute necessity and to avoid a catastrophic high-speed collision on a dangerous stretch of highway, the severely crippled vehicle had to be forced through active interstate traffic without proper engine power all the way to my home. The vehicle has since been inspected by a GMC dealership, which has confirmed that the exact same Cylinder 3 lifter has failed a second time. The dealership and the GMC Regional Service Manager are currently refusing to honor the 24-month dealer-installed service parts warranty, demanding an out-of-pocket deposit of $5,000, and denying alternative transportation. GM's failure to permanently remediate this known, systemic valvetrain defect has twice left me navigating a failing vehicle through high-speed highway traffic, heavily compounding the safety risk.
No injuries · No fire · No crash
On August 17th, 2026 while approaching a nature preserve entrance at approximately 1 mph, my 2023 GMC Yukon Denali Ultimate suddenly accelerated on its own, without the driver pressing the accelerator pedal, striking a split-rail fence and a tree. Airbags did not deploy. The front collision system didn't issue any alerts about the fence and tree. A GM software update had been installed a couple of days before this incident . In the weeks prior, the vehicle had also intermittently failed to hold side mirror position and periodically failed to deploy the power running boards. I request that GM and NHTSA investigate a possible link between the recent software update and an unintended acceleration event, potentially related to the adaptive cruise control or another driver-assist/body control module.
Engine shut off with no warning, all electronics disabled and couldn't shift out of park. Was driving down the road at approximately 50mph, Yukon shifted itself into neutral. Vehicle previously complied with the 25V-274 recall and passed, was operating on the new oil that GM recommended.
No injuries · No fire · No crash
Second engine sized at 87,834 miles. Third engine installed three weeks later.
No injuries · No fire · No crash