2019 GMC YUKON XL Power Train Problems

The vehicle experienced a lifter and valve train failure within the warranty period, as addressed in GM TSM MC-10209953. This failure can cause sudden engine noise, loss of power, and potential engine seizure while driving, creating a serious safety hazard for the driver, passengers, and others on the road. The component failure is reproducible and has been confirmed by a repair shop; it is available for inspection upon request. An engine rebuild was completed just after the warranty expired, and the manufacturer has denied warranty coverage and refused to address the issue. Prior to failure, no warning lights or messages indicated a problem, meaning drivers have little to no warning before a potentially catastrophic malfunction. Because this is a documented issue affecting multiple vehicles and the manufacturer is refusing corrective action, this defect presents a clear risk to public safety. I urge NHTSA to investigate this matter, determine whether a safety recall is warranted, and require the manufacturer to address this known defect to prevent accidents and injuries.

2019 GMC Yukon XL. Purchased pre-owned from a dealership in July 2023. This month, August 2025, my transmission has failed. Apparently this defect is notorious for this particular year of GMC Yukon XL. There was a lawsuit against GMC but it was closed in June 2025. The issue is real and widespread and GMC should ABSOLUTELY be responsible. There’s no reason a six year old vehicle should require this extensive repair.

See attached document for complaint.

December 28- Transmission goes bad, gets vehicle back Feb 17th - •Dangers include loss of vehicle control, wreck, cannot hit gas pedal. March there’s an exhaust leak. •Inhaling is dangerous as this contains carbon monoxide, potential fire, May y axle on muffler •Dangers include reduced engine performance that can lead to wrecks, carbon monoxide poisoning, and failed emissions test. July Engine failure in repairs until August •Can cause accidents August coolant leak •Can lead to engine overheating and lead to engine failure causing accidents. September unknown reason, car just keeps shutting off while driving. •Dangers in this one speak for themselves. Inspection can be done. Problems were confirmed but just keep continuing to occur. No warning signals, car just keeps breaking down for various reasons.

The contact owns a 2019 GMC Yukon XL. The contact stated that while reversing out of the driveway at approximately 2 MPH, the vehicle stopped moving. The contact depressed the accelerator pedal and the vehicle only revved. The contact stated that she was able to move the gear shift lever, however the vehicle was not responding in any gear. The contact stated there was no warning light illuminated. The contact had the vehicle towed to a local dealer, where it was diagnosed and determined that the transmission had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 78,000.

Mileage: 78,000

GM vehicles manufactured between 2015 – 2019 equipped with GM’s 8-speed transmission are equipped with a defective transmission design of GM’s Hydra-Matic 8L90 transmission or Hydra-Matic 8L45 transmission, which causes vehicles to suddenly lurch forward, shudder, and experience significant delays in acceleration. GM not only knew about this pervasive issue but developed a fix for it in 2018 – namely a transmission flush it calls Mod1a. However, GM made the business decision in 2019 to forgo recalling all impacted vehicles (approximately 2 million) to receive this flush, which would have cost GM about $305 per vehicle for a total $592 million, and instead decided to limit the flush to only unsold Cadillacs and trucks in certain states where it expected customers to complain within their warranty. Furthermore, GM never alerted existing customers of the issue or the fix and only addressed the issue if the customer was under warranty and complained about the shudder. GM marketed and sold these 8-speed automatic transmission vehicles as having “world-class performance,” lightning-fast and smooth shifting, along with improved fuel efficiency, and instead sold defective vehicles.” These conditions make it difficult to safely merge into traffic or back out of a garage/driveway. Even more troubling, the transmission defects cause the vehicle to delay downshifting and decelerating when the brakes are depressed. The affected vehicles include Chevrolet Silverado (2015-2019); Chevrolet Colorado (2017-2019); the Chevrolet Corvette (2015-2019); the Chevrolet Camaro (2016-2019); the Cadillac Escalade and Escalade ESV (2015-2019); the Cadillac ATS, ATS-V, CTS, CT6, and CTS-V (2016-2019); the GMC Sierra, Yukon, and Yukon XL, and Yukon Denali XL (2015-2019); and the GMC Canyon (2017-2019).

This car had catastrophic engine failure due to the lifters, push rods and camshaft. This car make and model and engine type is notorious for these specific parts to malfunction. This could have left myself and my children stranded on the interstate. The vehicle has been inspected by a certified master technician with ASE training. They confirmed that these parts are a common issue with these cars.

The contact owns a 2019 GMC Yukon XL. The contact stated while driving at an undisclosed speed, he heard an abnormal sound coming from underneath the vehicle. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a general failure with the transmission. The vehicle was repaired, but the failure recurred. The vehicle was taken back to the dealer, who again diagnosed a general failure with the transmission, and informed the contact that the transmission needed to be replaced. The vehicle was repaired; however, the failure recurred. The manufacturer was not notified of the failure. The failure mileage was 65,000.

Mileage: 65,000

I actually own two GMC's one is a 2018 GMC sierra and this vehicle and they both have transmission problems. This vehicle has 100,000 miles on it and the transmission is gone, you want to charge 70,0000.00 for a vehicle that has a sup par transmission and to replace it cost over 6000.00. The sad thing is when I pulled up to the dealership and told the sales manager and shop manager my problem they just shook their head and said it won't be good and that they have had to replace a lot of them, so many that they keep the transmission in stock like wiper blades. This is utterly ridiculous and I have bought and paid for at least six or seven GM products in my life but this will be my last one I promise you that.

The contact owns a 2019 GMC Yukon XL. The contact stated that after parking the vehicle and then later restarting the vehicle, it was discovered that the transmission would not shift into reverse(R) or drive(D). The vehicle was later towed to the local dealer. The cause of the failure was not yet determined. The manufacturer was not yet contacted. The approximate failure mileage was 83,000.

Mileage: 83,000

UNINTENDED SURGE OF ACCELERATION. WILL HAPPEN RANDOMLY ABOUT ONCE A WEEK WHEN UNDER SLIGHT ACCELERATION. IT FEELS LIKE THE ACCELERATOR GOES FULL THROTTLE FOR ONE SECOND, CAUSING A HUGE SURGE OF ACCELERATION, ALMOST PLOWING INTO THE CAR IN FRONT OF US MULTIPLE TIMES. THE LAST TIME IT HAPPENED WHILE IN REVERSE. DEALER EXAMINED THE CAR AND SAID THERE ARE NO CODES STORED IN THE COMPUTER AND COULDN'T REPLICATE THE PROBLEM. WE GET THE CAR BACK TOMORROW AND MY FILE DRIVES IT WITH OUR 4 KIDS, SO THIS IS VARY SCARY (FOR THE SAFETY OF OUR FAMILY AND OTHERS ON THE ROAD). DEALER SUGGESTED IF WE DON'T TRUST THE CAR, WE CAN HAVE CAMERAS INSTALLED IN THE CAR TO CAPTURE THE PROBLEM SO WE CAN SHOW THEM. WE HAVE VERY LOW CONFIDENCE IN THIS CAR AS IT IS DANGEROUS TO DRIVE. THE FIST TIME WE NOTICED THIS WAS IN THE AM, SO THE ENGINE WAS STILL COLD. STARTED ACCELERATING SLIGHTLY DOWN OUR RESIDENTIAL STREET AND THE CAR WENT TO FULL THROTTLE ON IT'S OWN FOR ABOUT 1-2 SECONDS (RPMS SKY ROCKETED). THE SECOND TIME WAS ABOUT A WEEK LATER WHEN MY WIFE WAS DRIVING THE KIDS TO SCHOOL IN THE MORNING (AGAIN WITH A COLD ENGINE). SHE PULLED OUT OF AN INTERSECTION AND THE HEAVY SUV WENT TO FULL THROTTLE ON ITS' OWN AGAIN, ALMOST CAUSING HER TO LOSE CONTROL. THE PROBLEM PRESENTS ITSELF ABOUT ONCE OR TWICE A WEEK. THE LAST TIME SHE WAS BACKING OUT IN REVERSE WHEN THIS OCCURRED, CAUSING HER TO ALMOST CRASH INTO SOMETHING. DEALER CAN'T FIND THE PROBLEM BUT THE PROBLEM EXISTS. THE ONLY THING IN COMMON BETWEEN ALL OCCURRENCE IS THAT THE ENGINE WAS COLD, THE AC WAS ON, AND THAT WE WERE UNDER LIGHT ACCELERATION WHEN THE SYMPTOM PRESENTED ITSELF.

Mileage: 10,000