2020 Gmc Yukon XL Complaints

My 2020 GMC Yukon XL Denali 6.2L with 59,000 miles developed a ticking noise and slight power loss diagnosed by three different garages as a "collapsed lifter" on #4 cylinder. It's one of the AFM/DoD cylinders that shuts down to save fuel. $8,000 repair estimate, or $12,000 if the failed lifter damaged the camshaft. All three garages said "we see a lot of these." Internet forums are loaded with lifter problems on this engine: specifically AFM/DoD lifters. Safety is not affected. Noise/diagnosis reproduced by three independent garages. Has not been inspected by mfg, police, or insurance rep. No warning lamps or messages, no ODB2 "codes" found by garages. Seven months ago the water pump exploded on Interstate 70, putting us at serious risk. Now this lifter trouble at 59,000 miles. Both should have been covered by the 60,000 mile powertrain warranty, but I'm beyond the 5-year limit.

Complete engine failure while driving on I25 in New Mexico, lost all power was able to roll into a airport parking lot. If I had not been close to the off ramp it could have been catastrophic with the truck traffic on the Interstate. The vehicle has completed all of its normal maintenance on time, and as of January 30, 2026 had a complete review from GMC that everything was in great shape including the engine. There was never a warning light, a maintenance message or any other indication.

My 10 speed transmission on my 2020 Yukon XL Denali experienced a total failure. The vehicle will not move under its own power. General Motors has ZERO information on when a replacement Transmission will be available. Some info online shows it could be months. I am told that one dealership out of Eden Prairie, MN has over 40 on back order and some since August 2025. They claim the issue stems from a valve body. Their communication has been terrible and no one within GM that I have spoken to has any information on what is being done. This is completely unacceptable and I believe it is part of a larger issue. They are making it seem like it’s not important and that needs to change.

I was traveling along i80 and suddenly the vehicle shutdown. I put the transmission in Neutral and coasted to a stop. Once stopped, I check It would not start or even turnover at that point. I still had all electrical services and such. The vehicle. I was stranded on i80. Then had to be towed to the nearest GM Dealer in Evanston Wyoming. Heritage Chevrolet GMC. It was left there for diagnosis where their technician, several days later diagnosed it with a bad engine. There was no warning or check engine light that appeared. I even have a picture from a little while earlier while driving earlier that morning. It took it because I was surprised it was getting 28mpg in v8 mode. but I am glad I had that photo to show no diagnostic lights were on.

Knocking noise from engine-no check engine light initially. Next time it was started knocking was still present and the check engine light was on. Contacted Champion Chevrolet in LaGrange KY. Dealership diagnosed problem (Code P0308 - Cylinder 8 misfire). Compression test on Cylinder 8 failed. Removed valve cover and confirmed loud tick in the rocker shaft and worn camshaft lobes. Was told I would need a new engine and that repairing the existing engine was not cost effective. So, $22,722.14 later, i have a new engine in my 2020 GMC Yukon and have the original engine (core charge) in my shop in case it is needed for evaluation to help determine if the GM recall should be expanded to 2020 model year (and others not covered by the current recall).