2023 GMC SIERRA 1500 Complaints

While driving my 2023 GMC Sierra 1500 Denali, 6.2-liter engine on the highway, the engine seized at 22,000 miles. GMC has been working on my truck since 9/7/24 and still no truck. The end state is, I was told by the Service Department that there is a design flaw with the 6.2-liter engine (something with the intakes valves being too large, resulting in the valve bending seizing the engine). I was also told, this dealer had two other trucks there now with the same seized engine. Their plan is to install a new engine with the same design flaw with the hopes it does not happen again. This was an extremely unsafe condition as I was travelling at 65 miles per hour on the highway when the engine seized, luckily, I was able to coast to a large shoulder after almost getting into an accident when it seized going uphill.

The radiator began leaking due to the fact it was falling out of the vehicle. The bolts holding it in became loose and just fell out. No lights or warnings were displayed on the dash to announce an issue was occurring even though the fluid levels had clearly dropped.

The contact owns a 2023 GMC Sierra 1500 equipped with a Roll-N-Lock tonneau cover. The contact stated that the tonneau cover failed to lock and latch securely since the vehicle was purchased brand new. The vehicle was taken to the dealer, where unknown repairs were performed; however, the failure persisted. Additionally, the contact stated that the latching part of the tonneau cover was missing an inch-long piece. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was unknown.

While at highways speeds, the steering will not return to center while going/coming out of a curve. It acts as if the power steering system is failing or low on fluid but that is not the case. I’m aware of a current recall with the Sierra but my VIN does not fall into the recall. The recall is for a software fix. GMC will not look into without charging me. This is a safety issue while driving. It holds the steering wheel in the turning position and I have to pull it to center.

Tailgate dropped while driving on the freeway. I was towing a utility trailer at the rime and the Tailgate hit the hitch area and scratched the Tailgate. It also dropped when not towing anything. I am leary to haul anything in the back of my truck

The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving at various speeds, the tailgate opened without driver input. The sensor failed to notify the contact that the tailgate was opened. The vehicle was taken to the dealer and the tailgate sensor was replaced. The failure persisted. The vehicle was returned to the dealer where it was confirmed that the VIN was not under recall. The vehicle was not repaired. The manufacturer was made aware of the failure. Vin tool shows no information. The failure mileage was 900.

Engine goes to limp mode multiple times 3 of which happened getting onto the highway and almost creating an accident due to the reduced acceleration mode. CODe u0656 00 popped up each time. Dealer has yet to rectify due to lack of appointments… making me keep the vehicle saying it’s drivable but each time randomly goes into the reduced acceleration mode every restart. (Blasius GMC Branford CT)

Approx 17 months after purchase, tailgate release button (the lower button on the tailgate that is used to open (fully) the tailgate) stopped releasing the tailgate, however tailgate releases randomly when opening one of the truck doors. Based on the "fix" that has been subscribed for existing Chevy & GMC trucks with recalls for this same problem (although my truck isn't covered by current recalls) , my mechanic has ordered a new tailgate release switch (or whatever it is called) which they are installing tomorrow.

In late February/early March, my GMC Sierra with around 9000 miles had the following to occur on a cold start: check engine light came on as well as the service esc light & traction control light, truck shuddered and shimmied. Took for service on March 4, 2024 with 9774 miles on odometer, where service tech said they couldn't duplicate concern (see attachments: March Service Invoice Pg 1 & 2). Took truck home & same issues kept occurring especially on cold mornings & days. Took the truck back for service on April 1, 2024 with 10895 miles on odometer. Told them to keep it till its fixed & to start it on cold mornings because thats when problem occurs. They had truck till April 12, 2024 and were able to duplicate the concern. Dealer changed the fuel injector (that was not the problem). Service tech finally found the cylinder 8 has a misfire until vehicle gets to operating temperature. They replaced all 8 lifters in bank 2 (right side) & gave me an oil change. This seems to have fixed the problem, but I won't really know until winter 2025. My problem with this lifter issue is that this engine will probably only last for 3 maybe 4 years tops because of all the metal shavings that are roaming around in the engine. This has been a problem with GM engines for some time & GM has yet to fix it or at least take responsibility for their poor engineering. I paid over $70,000 (of which GM made around $17,000) for this truck only to have the engine probably make it for a few years. My last truck I kept for 10 years. I don't see this happening with this truck.

after driving for a few minutes when down shifting vehicle will lock gears making the rear tires slide until a loud pop. May drive fine for a few miles again then reoccurring at any speed dealer said to drive it on SAFETY CONCERN but i did. truck has been at dealer for 2 months now. but am aware of more than mine with the same problem at the same dealership located at laura buick gmc in collinsville illinois