2019 GMC Yukon: sudden loss of power

Filed Aug 4, 2026 · Engine · TX

My wife drives this vehicle to work, it has started to experience reduced engine power driving on the highway causing her to pull to the side of the road due to no throttle to maneuver the vehicle in and out of traffic, leaving her on the side of the busy highway, we have now parked the vehicle after investigating problem there is a knocking noise coming from the lower part of the engine, after research of this 6.2l engine there are reports of the crankshaft and connecting rods seizing up and coming through the side of the engine block, knowing this we are hesitant to continue driving the vehicle. We continue to make payments on a vehicle that we can't use and can't afford to make a engine replacement at the moment. Very frustrating to say the least, as expensive as these vehicles are we have lost faith in the gm name.

Filed Jul 6, 2026 · Transmission · TX

The vehicle experienced a sudden and rapid mechanical failure of the 6-speed automatic transmission (6L80 model) within a span of less than two weeks. The light did not come on until the transmission was past salvage. The failure escalated rapidly from initial minor slipping to a severe loss of vehicle propulsion. A loss of acceleration while driving poses an immediate crash hazard, as the vehicle cannot safely maintain speed with surrounding traffic or accelerate out of dangerous situations. The failure required towing and a complete out-of-pocket replacement of the transmission unit at 116,374 miles to restore safe operation. The manufacturer has failed to issue a safety recall despite widespread failures of this component causing unexpected power loss on public roadways.

Filed Mar 18, 2026 · Engine · NJ

I was driving on RT80 in NJ and my 2019 GMC Yukon lost power. I took it to my local Chevy dealer. The scan code was p0300 engine misfire. They removed right side valve cover and found no bent pushrods. Inspected camshaft and found damage from failed lifter. I had to get a new engine and pay out of pocket $14,435.44

Filed Nov 18, 2025 · Engine · IL

MEMORANDUM To: the federal safety agency Subject: Safety Defect Report – 2019 GMC Yukon Denali 6.2L V8 (L87) with AFM/DFM I am reporting a serious and recurring safety defect involving my 2019 GMC Yukon Denali equipped with the 6.2L V8 L87 engine and GM’s AFM/DFM system. In the past twelve months, I have experienced two separate engine failures, both occurring at highway speeds and both involving valve-train/VLOM failures on the same side of the engine. In each incident, the vehicle suddenly lost power, misfired violently, and became unable to maintain speed. This created an extremely dangerous situation for my family. One failure occurred while my wife was driving; the other occurred while my [XXX] son was driving. Both were forced to maneuver across high-speed traffic with a failing engine to reach the shoulder. These events posed a clear risk of a high-speed crash, injury or even a fatality. There are hundreds—possibly thousands—of documented complaints from owners of GM vehicles with AFM/DFM-equipped engines reporting the same issues: collapsed lifters, valve failures, VLOM malfunctions, and sudden loss of propulsion. These failures often occur without warning and show a consistent pattern across multiple model years and engine variants, including the L87. The sudden loss of power at highway speeds represents a significant safety hazard. The frequency of similar reports suggests a systemic mechanical defect rather than isolated incidents. I respectfully request that the federal safety agency open a formal investigation into AFM/DFM-related failures in GM’s L87 and related V8 engines, with a focus on lifter, valve, and VLOM failures that lead to abrupt engine shutdown. Appropriate safety action, including a mandatory recall, should be done immediately to prevent potential injuries or fatalities. I will provide repair documentation, service reports, and other additional information. [XXX] , Esq. [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B

Filed Feb 23, 2020 · Driver assistance, Electrical · 34,800 miles · IN

Loss of power steering, loss of electronic stability control, loss of all transmission gears forward and reverse, loss of automatic headlight control, loss of instrument cluster gauges including tachometer, engine oil pressure, and engine coolant temperature, loss of heated seat functionality, loss of heating, ventilation, air conditioning, and loss of infotainment/stereo system. This problem has occurred on two occasions now, the first on 01/13/2020 and then again on 02/20/2020. The vehicle was towed in to the dealer on 01/13/2020 and was also transported to the same dealership again on 02/20/2020. A tsb was performed by the dealership when it was towed in the first time that obviously did not fix the root cause of this problem. Normally the problem will go away after a period of time and then the dealership claims that they were not able to reproduce the customer's complaint. I do have video footage of the issues I experienced on two occasion as proof.

Filed Jul 29, 2019 · Steering · 6,408 miles · NC

2019 gmc yukon denali. 6408 miles. Driving down the highway at normal speed a warning appears that says service power steering. Immediately lost power steering on the vehicle and by the time we got it to the off ramp the steering was completely locked in the straight position. Very fortunate that this did not happen on one of the many curved roads where we live. We had no warning.