2019 GMC Sierra 1500: water leaks into the cabin

Filed May 30, 2026 · TX

Back window water leaking causing bad smell and mod

Filed Dec 6, 2025 · CA

Experience water leaking 3rd brake light and rear window. Leaking in both areas. Also concerned about mold that could be caused by this.

Filed Aug 13, 2025 · Electrical, Engine · GA

Subject: Urgent Vehicle Safety Complaint – 2019 GMC Sierra Denali Escalating mechanical and electrical failures — many beginning before 100,000 miles, and continuing as of today, at approximately 110,000 miles. These issues have made the vehicle unreliable and unsafe to drive. Since purchasing the vehicle, I have had it serviced regularly and reported that it was driving rough, jerking into gear, and showing early signs of engine and transmission problems. These issues were noted during multiple multipoint inspection services, yet no lasting solutions were provided. Major issues have included: •Engine performance failures •Fuel injector malfunction •Serpentine belt and idler pulley damage •A/C compressor belt failure •Power steering malfunctions •Vehicle stalling at traffic lights •Loss of power on major highways •Rear window water leaks •Significant and ongoing electrical system problems •Shaking when brakes applied after having brakes and rotors replace in March •Screen monitor going out after paying over $ 900 dollars for updated software and repairs to the electronic component that cost over $2500. Despite continued maintenance, on Thursday, July 3, 2025, my truck began losing power and smoking heavily while driving on a busy highway in Georgia. My grandchild, who was riding with me, yelled, “Grandma, it’s smoking — please get out!” as we pulled off the road in fear of a fire. This terrifying incident left us stranded and emphasized just how dangerous this vehicle has become. I filed a formal complaint with the GMC Corporate Office, but no support provided or an investigation. Over the past six months, I have spent more than $5,000 trying to keep this vehicle operational. So many critical systems have failed, despite consistent maintenance, raises serious concerns. Finally, the fuel injector repaired 3 days later a message on dashboard displaying service Tire monitor system and steering wheel shaking when brakes are applied.

Filed Apr 27, 2025 · Body, Electrical · WI

Rear sliding glass window is leaking water around the exterior frame. This is addressed in TSB 18-NA-383 but not covered under any warranty. My rear seats and carpet are becoming wet. I am concerned about the possibility of mold and an electrical short/fire resulting from water intrusion. There are many reports and discussions on the internet regarding this issue. Full window replacement estimated at $1300. Patchwork repair with caulk is estimated at $600 with no guarantees of success. I would expect GMC to cover the replacement of the rear glass in kind and remedy any other damage to my vehicle due to water intrusion into the cabin area.

Filed Jul 23, 2024 · Body, Visibility · MO

Rear 3rd brake light and rear window are leaking water into the cab causing visibility issues.

Filed Nov 18, 2023 · Body · CA

Rear window is leaking water inside cab and may cause mold

Filed Nov 9, 2023 · Electrical · TX

There is a water leak coming into the back cab of my 2019 GMC Sierra. My truck smells horrible the dealership can't find the leak. It smells very moldy and very concern for my children riding in the back breathing the unsafe air.

Filed Dec 13, 2022 · Body · NY

The rear window on the 2019 GMC Sierra SLT leaks water into the cab. This presents a serious concern to the owner of the vehicle because unless you are specifically looking for the leak you may not even know there is one. Upon noticing the leak, one can witness a steady drip of water behind the rear seat, drivers side. My personal concern is that what happens after the water has leaked and had gone unnoticed for an extended period of time, does mold start to grow? Does my truck have mold growing in it? With two young children in the vehicle I am concerned about their health and safety. My frustration with this issue is that GM refuses to acknowledge that there is an issue. My dealer has brought this issue up with GM but the claim has been denied. I have no idea how long the leak has been happening but it’s a manufacturing problem that exists and it certainly shouldn't be the owners responsibility to fix the problem. More importantly, it shouldn't be my young childrens health that is affected by the manufacturers incompetency and ignorance.

Filed Nov 9, 2022 · Body, Electrical · IA

My 2019 2500hd (49,00 miles) truck had water leaking in through the roof. The dealership found that the leak was caused by a bad factory tack weld on the passenger side roof seam. Due to this bad tack welkd, it caused water to leak down the a-piller, down into my electrical fuse box and wiring.

Filed Apr 13, 2019 · Body, Electrical · 200 miles · TX

First week of ownership I noticed that the rear window had a water leak by rear driver seat. While inspecting the leak, I notice that the paint on the rear brake spoiler above the rear window had two black marks. Body shop technician rubbed his fingers on the spots and paint was rubbing off. I started to receive 'service steering column lock' messages intermittently and regularly during startup. Heating indicator lights for all the seats do not light up to indicate their settings. This occurs while vehicle is stationary or on the road. The rear backup camera screen turns blue and displays 'service rear backup camera' while reversing and it occurs occasionally.