GMC Complaints

As my wife was driven she heard some noise and notice she was losing power. She pull off the side of the road and the car shut off. Could not restart. This happen about 11:30 am on 8/14/26 Got towed to Salida Dealer called Faricy GMC about 3:30 pm. Dealer said it was a complete engine failure and engine needed to be replaced.

I know an engineering analysis has been opened on the 6.2L motor for GM models. I just want on the record that my wife has a 2022 GMC Denali XL that had the engine replaced in December 2025. After that motor replacement it repeated the same issue July 4th 2026 and the dealership replaced the engine a second time for the same reason, and I will be attaching each invoice for both replacements. Just want to have the #'s updated to show the remedy doesn't seem to work or in my case it didn't and I have seen numerous news articles talking about this.

Driving at highway speed vehicle began making odd engine noises and then lost power, pulled over and power continued to diminish until vehicle was no longer operable.

While driving in passing lane on interstate highway at approximately 65 mph engine lost power. Dashboard warning "vehicle in neutral" message appeared. "Press start" message appeared. Tried to start the engine but did not start. Slight downhill while on highway and had to make it to right shoulder since no shoulder on left side of highway. Glided across 2 lanes to right lane and luckily an exit came up while still gliding slightly downhill. Exited ramp and got off highway to an empty parking lot. Put vehicle in Park. Since engine failed, power steering was normal as was all electrical components. Once stopped, vehicle was not able to be shifted into Neutral. Message " unable to shift to Neutral under conditions " appeared. Vehicle had to be towed with rear wheels on dollies since it was stuck in Park. Was very lucky to get vehicle across lanes of traffic and off highway to a safe location. Had vehicle towed to nearest GMC dealership where it was diagnosed as internal engine failure covered under recall for this particular engine. (6.2 liter).

This truck has the GM L87 6.2L engine that is currently on recall for 2021- 2024 model years, but recently the NHTSA is looking into post engine replacement failures and 2025-26 model year issues. My engine at 7,000 miles failed for rod bearings. Same issues reported years ago and 100k engines ago. GM has not fixed the problem, its still happening.

This truck was bought brand new by my father. Around 38,000 miles it begin having issues with shifting which eventually got worse. When I searched google for issues many others on different pages have had the same issues. The shifting would be so rough it feels like you're being hit by another vehicle. This could cause accidents for anyone who cannot afford to fix these known issues by GMC. I was told today by my local dealership their transmissions for my specific truck is on backorder. Should that not indicate an issue when this truck is a 2020. But to my father having a stroke I was not able to handle this issue sooner as he was very ill for four years and passed last year. The truck was not the priority at the time.

Misfire on 2 cylinder, noise on start up diagnostic code P0300 P0302 P050 I was driving home and the engine started making a strange sound, vehicle would could no increase speed normally. The dealership did basic analysis from the onboard computer and did a compression test. Heavy knocking sound on passenger side of the engine. The issue happened on Aug 5th 2026. The issue is due to the AFM that causes the lifter to fail and dealership says I need a new engine $15787 or replace cam shaft $14530.

My vehicle had a previous engine recall that was “fixed” per the dealership recommendations. However, I succumbed to total engine failure last week at 70000 miles with my 2 little kids in the car on an interstate. My engine needs replaced.

The control valve body failed. There are so many, that there was a shortage of parts. Had to take it in as it went into limp mode. 34,000 miles. There were dozens of trucks, same year, waiting for the same repair. Shop says probably every truck will need it. It is a known issue.

I am reporting a severe, recurring, and life-threatening manufacturing defect involving a sudden, catastrophic loss of motive power at highway speeds on the interstate. This vehicle has suffered two identical valvetrain failures that placed my passengers and nearby motorists in extreme danger. Incident 1 (Approx. 40,000 miles): While traveling at high speed on the interstate, the vehicle violently shook, all engine warning lights flashed, and the engine suffered an immediate, near-total loss of propulsion. The vehicle was towed to an authorized GMC dealership, where technicians diagnosed a collapsed Dynamic Fuel Management (DFM) hydraulic lifter in Cylinder 3. The lifter bank was replaced under the factory powertrain warranty. Incident 2 (Approx. 77,000 miles): While driving at high speed on the interstate, the exact same vehicle behavior occurred. The engine suffered a sudden, total loss of power, and all dashboard warning lights illuminated simultaneously. Out of absolute necessity and to avoid a catastrophic high-speed collision on a dangerous stretch of highway, the severely crippled vehicle had to be forced through active interstate traffic without proper engine power all the way to my home. The vehicle has since been inspected by a GMC dealership, which has confirmed that the exact same Cylinder 3 lifter has failed a second time. The dealership and the GMC Regional Service Manager are currently refusing to honor the 24-month dealer-installed service parts warranty, demanding an out-of-pocket deposit of $5,000, and denying alternative transportation. GM's failure to permanently remediate this known, systemic valvetrain defect has twice left me navigating a failing vehicle through high-speed highway traffic, heavily compounding the safety risk.