Gmc
Yukon

MEMORANDUM To: National Highway Traffic Safety Administration (NHTSA) 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 NHTSA 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)(6)

Four of the eight oil lifters in my 6.2L engine in my 2019 GMC Yukon failed. The car has around 53,000 miles. The issue was confirmed by an independent service center. There were no warning lamps or messages prior to the issue. Zero. The service center even ran diagnostics with no result and could not confirm the issue until after it partially took apart the engine. I noticed a noise similar to a card flapping in the wind and took it to the service center that same day. The car had been properly serviced with oil changes and still had 44% oil life that same day. Repairs are currently being made and estimated at $4,000.

Driving out a town 400 miles away, with a young passenger in my car on [XXX] in rush hour traffic, i started hearing a slight ticking sound then moved into a full blown knock on my drivers side ( I recorded it). within minutes, my oil light came on and my dash notification reading "engine overheating idle" with the knocking really load. I had to cross 3 lanes to traffic quickly to get to the shoulder of the road, which was NOT a safe place. I smelled smoke and cut the the engine off. I popped the hood to see that there was now no coolant (that is all I knew to look for). I immediately called OnStar Roadside assistance. 2 hours later, I was towed to a local hotel room. Car completely dead. not lights, couldn't lock it, nothing. I had to pay a large fee (almost $2k) to have my car towed back to NC from AL not to mention having rent a rental car to get us home. the car is now at a GMC dealership in Monroe NC. of course the Powertrain extended warranty doesn't cover the Battery replacement, belt replacement and water pump replacement so now I'm out of pocket $1300 just to get those install to be able to try and start the engine to further diagnose if my I have complete engine failure AND without transportation. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I JUST PURCHASED THIS 2019 GMC YUKON DENALI. ABOUT 3 WEEKS AFTER; THE MESSAGE "SERVICE TRAILER BRAKE SYSTEM" STARTED BEEPING...DIDN'T REALLY PAY BOTHER ME AT 1ST SINCE I WEREN'T PLANNING TO PULL ANYTHING. THEN IT STARTED DOING IT MORE FREQUENTLY. NOW IT IS CONSTANTLY DOING IT EVERY FEW DAYS. CAN'T SEEM TO GET IT TO STOP. VERY ANNOYING... ANY SUGGESTIONS?

The contact owns a 2019 GMC Yukon. The contact stated that while driving at an undisclosed speed, the vehicle briefly hesitated and jerked before returning to normal functionality. The check engine warning light was illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the transmission. The contact was informed that the transmission needed to be replaced. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 111,000.

The contact owns a 2019 GMC Yukon. The contact stated that upon starting the vehicle, there was an abnormal knocking sound coming from the engine, and the engine failed to run. The message "Shut off Vehicle - Service at Local Dealer" was displayed; however, no warning lights were illuminated. The vehicle was towed to a local dealer where it was diagnosed, and the contact was advised that the lifters, cam shaft, and push rods were faulty and needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The approximate failure mileage was 76,300.

The contact owns a 2019 GMC Yukon. The contact stated while driving 40 MPH, there was an abnormal ticking sound coming from the vehicle. There were no warning lights illuminated. The vehicle was taken to the local dealer where it was diagnosed and determined that the water pump needed to be replaced. The vehicle was repaired; however, the failure recurred. The vehicle was taken to the dealer where it was diagnosed with engine failure, and lifters and cam phaser failures. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was approximately 7,000.

Engine lights and all other warning lights came on, and lost total power in engine while driving. Engine knocked bad and had to limp to a repair center to check out engine problem. Service department says total engine failure at 72k miles, no warning. Apparently this 2019 GMC Yukon is not within the recall for engine replacement that appears it needs to be covered as well.