Body Problems of GMC Sierra 3500

While traveling at highway speed, the hood-mounted air vent (factory-installed component) on my 2022 GMC Sierra 3500 hd suddenly detached from the vehicle without warning. Upon separation, the vent was propelled backward, striking both the hood and the windshield. The incident occurred during normal driving conditions, with no prior indication of looseness, damage, or defect in the component. The force of the detachment caused damage to the hood and posed a significant safety risk, as the debris impacted the driver’s line of sight and could have resulted in loss of control or injury. There were no external factors (such as collision or road debris) that contributed to the failure. This appears to be a failure of the factory-installed component and its mounting system. Safety concern: this type of failure presents a serious hazard not only to the vehicle occupants but also to other motorists. A detached component at highway speed could strike nearby vehicles, cause sudden driver distraction, or lead to more severe accidents.

See all problems of the 2022 GMC Sierra 3500 🔎.

Known defect with 2019 and now 2020 GMC sierra trucks. Design was updated for 2021+ which has corrected the seal failure defect. Gm has issued a service bulletin to dealers about how to repair the problem. Back window is leaking water. Defective seal noted by gm. Gm is only covering the cost of repair if. Vehicle is still under 3/36 warranty. If outside your warranty cost from dealer to owner is $2500 to $6000. A known design failure gm recognized and took steps to change the design for future. Vehicles but will not stand behind vehicles that have this defect. Would like the cost to the repair fall back to gm to cover. Bulletin # 18na383 [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2020 GMC Sierra 3500 🔎.

Front wheel well liners keep falling out of place like they are melting. Happens when towing and engine gets hotter than normal. Trailer is well below limit for vehicle. Liners fall onto the tire while in motion. This is the 4th time this issue has happened to my vehicle. Dealer replaces them and says it happens all the time.

See all problems of the 2024 GMC Sierra 3500 🔎.

Tail gate has opened twice while driving down the road.

See all problems of the 2025 GMC Sierra 3500 🔎.

The vader chrome on the front of vehicle is peeling. This includes the grille and surrounding areas. This area has been inspected by a representative at GMC and at a dealership. GMC refuses to stand by their product.

On at least 5 occasions, my inner tailgate has released itself and gone down during motion. This has been uncommanded. It appears gm has a recall for this but it does not include my truck. The dealership that looked into it agrees this is likely the same issue and gm should include it in the recall.

1 - the failed component is the tailgate. The tailgate lowers automatically without any input from me while the vehicle is in operation. It has happened three times since buying the truck in February 2024. 2 - during the third event, I was backing up my airstream trailer into its storage building when the tailgate dropped. At that time, I was negotiating a sharp turn in reverse and the tailgate came in contact with my trailer's propane tank housing. Both the tailgate and the propane tank housing were damaged (see photos). 3 - it was not until recently that I learned of a recall for the same condition on other trucks like mine, but for some reason my truck doesn't seem to be included even though it has the same condition as those trucks that are included. The tailgate and my trailer have not yet been inspected by any third parties (manufacturer, police, insurance, etc. ), and no repairs have been made yet. 4 - there were no warning signals (either visible or audible) that the tailgate was down while the truck was in operation.

Water leak at the rear window leading to mold growth. Continues to leak after repaired twice by dealership.

There is a current safety recall n232426400 on GMC pickups including the year of my truck. GMC is saying that my VIN is not covered by the recall. However, I have the multi-pro tailgate and it came open about 6 months ago on its own as I was backing up and it caused me to run into my trailer with the tailgate. I put my tailgate up after moving my truck from under my trailer and then when I went to back up somehow the tailgate popped open and I didnt know and it contacted the top of tailgate while it was down.

Rear window leaking on 2020 GMC truck due to faulty rear window seal and plastic slide. Known issue in 2020 models with a service bulletin already in place. Headliner saturated and black mold showing. Rear back liner has been saturated multiple times and GMC would not refund the cost of a whole new window to be put in and reimbursed. Gm bulletin # is 18-na-383.

Plugged in engine block heater and the car erupted in flames. Total loss.

Tailgate falls open while traveling down the road.

See all problems of the 2021 GMC Sierra 3500 🔎.

I almost ran into another car because the other driver stopped suddenly and I had to pump the brakes over and over to stop when the rusted line broke. I was on a city street driving speed limit and was lucky to be able to stop. I was towing my trailer last week and almost lost the trailer because the entire underbody is rusted. I have had several trucks and never have seen this happen. It was a scary situation in both cases.

See all problems of the 2001 GMC Sierra 3500 🔎.