2021 GMC Yukon XL: shudder or vibration when accelerating

Filed Nov 4, 2026 · Engine, Fuel system · MI

INCIDENT 4: Fuel Injector Internal Short (Cylinder #6) Component / System Failed: Fuel Injection System / Cylinder #6 Fuel Injector & Wiring Harness Failure Description: Cylinder 6 fuel injector failed due to an internal electrical short circuit, causing immediate engine misfires and severe power reduction. Repair required replacing the Bank 2 fuel rail, four fuel injectors, and the injector wiring harness. Safety Risk: Immediate engine shuddering and abrupt drop in drive power while operating in active traffic creates a serious loss-of-acceleration hazard and heightened risk of a rear-end collision. Dealer / Repair Shop Confirmation: Official diagnosis confirmed by Service Center Technician via electronic diagnostics verifying the internal electrical short circuit. Warning Symptoms: Check Engine Light illuminated simultaneously with engine shaking and sudden power loss; no prior symptoms existed before the failure. Inspection Availability: Confirmed via technician diagnostics; Check Engine light illuminated along with four other warning lights- car had to be towed to dealership to be fixed

Filed Sep 1, 2026 · Engine, Transmission · IL

Vehicle is equipped with the 6.2L L87 V8 engine. Prior to receiving the dealer service for Recall 25V‑274, the vehicle experienced a distinct highway vibration, powertrain shudder, and fluctuating/jumping RPMs on the highway. The dealer subsequently performed the recall remedy by updating the vehicle to the thicker 0W-40 oil specification. However, the underlying transmission torque converter had already suffered catastrophic failure due to the powertrain stress/shudder and required a complete transmission replacement at 84,000 miles. I am reporting this because the initial 6.2L engine defect and subsequent recall remedy overlap heavily with severe powertrain and torque converter failures at low mileage

Filed Apr 9, 2026 · Engine, Transmission · 64,000 miles · IL

The contact owns a 2021 GMC Yukon XL. The contact stated that while driving approximately 70 MPH, the vehicle started shuddering and was losing automotive power. There was no warning light illuminated. The vehicle was taken to an independent mechanic to be diagnosed, and it was determined that the transmission needed to be replaced. The contact stated that it was the second transmission failure in less than 2 months. The vehicle was repaired. The contact was advised by the mechanic that the manufacturer had recommended a diagnostic test on the engine. The diagnostic test had not yet been performed. The manufacturer was informed of the failure. The failure mileage was approximately 64,000.

Filed Jul 11, 2025 · Transmission · 66,000 miles · OR

The contact owns a 2021 GMC Yukon XL. The contact stated while driving 70 MPH, the vehicle shuddered abnormally with the check engine warning light illuminated. The contact received notification of the federal safety agency Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was not yet available. The vehicle was taken to the dealer where it was diagnosed and determined that the transmission control valve had failed and needed to the replaced. The vehicle was not repaired. The dealer confirmed that parts were not yet available. The manufacturer was not made aware of the failure. The approximate failure mileage was 66,000. Parts distribution disconnect.

Filed May 21, 2025 · Engine · 73,000 miles · TN

The contact owns a 2021 GMC Yukon XL. The contact stated while her husband was driving at an undisclosed speed, the engine made an abnormal loud sound, and the vehicle became undrivable. The vehicle was taken to Midas, where an unknown repair was performed. Additionally, the contact stated while driving 50-55 MPH on the expressway, the vehicle shuddered significantly, and the engine made an abnormal loud knocking sound. Unknown warning lights were illuminated. The contact was able to exit the expressway and drove back to Midas, where the contact was informed that the engine needed to be replaced, and the mechanic provided an estimated fee for the repair. The vehicle was towed to the dealer, where it was diagnosed that the engine needed to be replaced; however, the part was not available. The vehicle remained at the dealer for approximately three months. The vehicle was not repaired. The contact related the failure to the federal safety agency Action Number: PE25001(Engine, Engine and Engine and Cooling). The manufacturer was notified of the failure and informed that the part was not available. The failure mileage was approximately 73,000.

Filed Apr 9, 2025 · Engine · 75,000 miles · OR

The contact owns a 2021 GMC Yukon XL. The contact stated that while driving at various speeds, the vehicle shuddered. The vehicle was taken to the dealer, where it was diagnosed that the lifters had failed and needed to be replaced. The manufacturer was contacted and informed the contact that only one side of the engine lifters replacement was covered. The vehicle was repaired accordingly. Additionally, the contact stated that while driving 55-60 MPH, the engine started shuddering. Several unknown warning lights were illuminated. The messages "Service ESC", "Forward Collision System Unavailable", "System Failure", and other unknown messages were displayed. The contact was able to drive to the residence. The vehicle was towed to the dealer, where it was diagnosed that the engine was blown and needed to be replaced. The vehicle was repaired at the contact's expense. The contact related the failure to the federal safety agency Action Number: PE25001 (Engine, Engine and Engine Cooling). The manufacturer was notified of the failure, but no further assistance was provided. The failure mileage was approximately 75,000.