GMC Complaints

This is a follow-up to my previous complaint - 11716917. My second engine, which was installed after my first engine failed after approximately 5,000 miles, also failed. It failed after approximately 5,200 miles on it. I picked up the vehicle after the first engine replacement on 2/19/26 and the second engine failed on 5/18/26. It failed as I was driving to work - I was able to exit the highway and pull into a parking lot. From there I had the vehicle towed to a dealership and they confirmed that the engine had failed and needed a total replacement. This is a 2026 Yukon XL Denali Ultimate with the 6.2 L87 engine. I want to make sure the NHTSA is aware that I’ve now had two complete engine failures and am on my third. I have no confidence in the vehicle and have no reason to believe that my third engine will last. GM has refused to do anything about this vis-a-vis extending my warranty or replacing my vehicle or buying it back.

My 2023 GMC Yukon Denali XL, used as a commercial vehicle for my business, experienced sudden and complete engine failure at approximately 70,000 miles with no prior warning. No check engine light, no unusual noise, and no other symptoms. The vehicle had previously been inspected/serviced under GM Safety Recall 25V-274 (L87 Engine Loss of Propulsion) and had been deemed safe prior to this failure. The failure occurred while driving on a two-lane road in Durango, CO. The vehicle lost all propulsion and came to a stop in the roadway, blocking the lane of travel and forcing other vehicles to cross into the oncoming traffic lane to go around the disabled vehicle. This created a serious and immediate hazard to myself and to oncoming traffic. The vehicle was not driveable and had to be towed. The dealer confirmed catastrophic engine failure requiring a complete engine replacement. After the engine replacement, the Morehart Murphy GMC dealership in Durango also failed to properly recalibrate vehicle sensors. They did not reinstall certain suspension components that had been removed for the engine replacement, requiring multiple additional dealership visits to resolve along with recalibration of the air ride suspension. After the replacement I was getting messages that the vehicle was "too low to drive with caution" and "Reduced Acceleration Drive With Care." This vehicle failure occurred during our peak season (June 10-July 2). The vehicle being out of service, I was required to rent a replacement vehicle at my own expense because GM did not provide a loaner vehicle. I estimate loss revenue at $1k/day. When I attempted to raise this issue with GM directly, their response was to submit letter to a P.O. Box, with no other means of resolution or contact offered. Given that this vehicle had already undergone the recall remedy and was represented as safe, this incident is relevant to NHTSA's ongoing investigation into post-recall L87 engine failures (Recall Query RQ26001).

1. What component or system failed or malfunctioned, and is it available for inspection upon request? The engine oil consumption system/engine is experiencing excessive oil consumption. My 2021 GMC Sierra is equipped with the 6.2L engine, and the engine is consuming oil at a rate that I believe is abnormally high. The vehicle and engine are available for inspection upon request. I am also concerned that my vehicle may be affected by an engine-related recall or safety campaign associated with this engine. When attempting to verify the recall status, the system appears to have an error and is not identifying my vehicle. I am requesting that the vehicle’s VIN and engine configuration be manually verified against all applicable recalls and safety campaigns. 2. How was your safety or the safety of others put at risk? The excessive oil consumption creates a potential safety concern because I am concerned that the engine could become critically low on oil while I am driving, potentially resulting in engine damage, loss of power, or complete engine failure. This could occur while traveling at highway speeds or in an area where it may be difficult or unsafe to stop. I regularly travel with my family, which increases my concern about the possibility of an unexpected engine failure and the potential risk to my passengers and other motorists. 3. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. I previously addressed this issue with Newton Chevrolet in [XXX], and later took the vehicle to Malcolm Chevrolet in [XXX], after continuing to experience concerns about excessive oil consumption. Malcolm Chevrolet tested the vehicle and confirmed that it is consuming oil at an excessive rate. The prior visit to Newton Chevrolet and the subsequent confirmation by Malcolm Chevrolet demonstrate that this concern has been reported and evaluated by more than one dealership. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

While traveling on [XXX] from Houston back to San Antonio, my truck engine just blew up without any warning whatsoever. We purchased the truck with 3 miles on it, and we have only put 5,000 miles on it. New cars that cost early $100K shouldn’t be having engine failures like this. I’m lost for words now! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I own a 2023 GMC Sierra 1500 Denali Ultimate equipped with the 6.2L L87 V8 engine. The vehicle previously experienced an engine failure that resulted in the complete replacement of the 6.2L engine by an authorized GMC dealership. The replacement engine was installed at approximately 76,316 miles. After approximately 1,000 miles of driving with the replacement engine, at approximately 77,354 miles, the vehicle displayed a check-engine/service warning and experienced abnormal transmission shifting. I returned the vehicle to the GMC dealership for diagnosis. The dealer documented DTC P0747, identified as “Transmission Control Solenoid Valve 1 Stuck On,” and recommended replacement of the transmission control valve body at a quoted cost of $2,665.85 plus tax. The dealership has stated that this transmission condition is unrelated to the recent engine replacement. However, because the condition appeared only approximately 1,000 miles after a complete engine replacement, I have asked General Motors to investigate whether the current failure could be associated with the previous engine failure, the engine replacement procedure, or other related vehicle systems. I have opened a case with General Motors Customer Assistance and have deferred the customer-paid valve-body repair while GM reviews the matter. I am submitting this complaint so NHTSA/ODI has a record that this vehicle experienced a major 6.2L L87 engine failure requiring complete engine replacement and then, approximately 1,000 miles after that replacement, developed a check-engine warning, abnormal transmission operation, DTC P0747, and a condition requiring replacement of the transmission control valve body. I can provide the engine-replacement repair order, current diagnostic documentation, mileage records, dealer repair estimate, and GM case information upon request.

This is the second time I have noticed storm heavy rain that my car is taken on water. We had an extremely heavy rain in June and no windows was left open. I did not know water had gotten into my car for an entire month when I heard a solution sale when I came to a break, what I did realize is that there was condensation buildup is inside of my car, but it was not sure why. After searching, I was able to locate and discover thatI had at least 3 inches of water standing water in my spare tire, section of my trunk. There was also an extreme amount of water on my floors in the back row once I took out my mats, I found there to be mold back there.Still unsure of how t the water got into the car I used my shop vac to suck out the water. We just had an extreme amount of heavy rain again. We are now in August. We just had extremely heavy amounts of rain and once again there’s water in the well trunk of my car where the spare tire is. I actually made sure to sit outside in my car during this heavy rain storm to see where the water was coming from. It appears that the water is coming from the sunroof, which then leaks to the back on the right hand side where the outlet socket is. I watched it dripped down into the back of the trunk into the spare tire well. I do not understand why this issue has not triggered a a recall yet as I’m noticing this is not just with my car. This is apparently the sixth or seventh car that has experienced this issue and GMC has yet to do a recall on it. This is very alarming and concerning God forbid I’m driving to work or I have one of my children in the car during a heavy rain storm and it hits the electrical wires or electrical panel with something else bad happens.

No warning the car made a loud clunk that shook the car. The engine began a severe knock with almost compete loss of power. The dealer confirmed the entire engine had to be replaced. I was told my car passed the PICO test recall and only required an oil viscosity change. There is something very wrong here. These engines are not right. I have handicapped twins and have zero confidence it won't leave my family stranded.

engine was replaced by Classic GMC in Katy/Houston, TX in dec 2025 under L87 recall. My wife was driving and was stopped on an off-ramp but still in the traffic lane. It started with a light knock that i thought i heard the day before, but then died on freeway within maybe 15 miles of her driving. Unknown if it knocked louder, but wife says she never heard anything until it died and check engine light came on and engine would not restart. Required tow to GMC dealer. They diagnosed and took 2-3 weeks to source and replace the engine. In july 2026, started hearing very similar noise - this time apparently the water pump seized. Heard noise and got home within about 10 miles. Checked under hood and drive belt was significantly frayed and knocking/metallic noise was intense. Towed to Classic GMC. Not covered under any warranty - my replacement engine did not include a new pump. Cost $1700 at Classic GMC - they said it had no relation to the engine replacement or labor done in December. Unrelated, but icing on the cake - less than 2 hours and 10 miles of picking it up from service, lots of warnings about lane keep, adaptive cruise control, and park sense started going off. Returned to same shop the next day and *poof* the camera and processor that runs all those systems was somehow fried. Unrelated of course. $1200 a but they claimed GM graciously offered to “split the cost with me 50/50” since I just paid so much for the water pump. Picked up from service and traded vehicle in with 2 days.

L87 Engine failed 6 months after replacement. Had to get 2nd full engine replacement. The car is currently on its 3rd engine. 1st replacement 10/16/25. Engine failed on 4/30/26. 2nd replacement 6/1/26.

I purchased this truck from a used car dealer. It had received the fix in January this year. They sold it to me I put 15,000.00 down and financed 15,000.00. I had the truck two weeks and was driving down the road to pick up some tools from a friends. I pulled from a drive way I heard a pop likei hit something In The road nothing was in the drive or road I could have hit. I made it two stop signs to make the turn too go pick up the tools and as I am slowing down to stop the stuck shuts off at like 45 miles an hour and leaves me comming to a stop with a truck crank crank crank no start. Cause it said shift I to neutral to restart. I did and the engine went to cranking over and o er really fast. And I was Abel to get control and get stopped at stop sign blocking the stop sign and a guy with a boat behind me. My friend came with his truck and pulled me from intersection up into His yard. And I had car lot I bought it from come get it they tried to finance me a motor thru there prefers dealer. I went to them they explained that the cams and timing chain was staying still as they turned the engine Over by hand. The timing chain stayed staionary. I researched the truck online figured out there is a l87 recall and had it taken to dealer they are offering good will payment on labor because it is 6, 000 miles past the 150000 dead line Wich I only placed just over a thousand of the 156000 miles on this truck. I have been without this truck for 31 days as of today. And I feel they should replace entire engine. I Am so frustrated with this cause I already payed 15000 and don’t have the money to fix this truck.