2020 Chevrolet Silverado 1500 body problems

Filed Oct 13, 2026 · Body · ME

GM Corporate Legal has formally denied a repair for a known design flaw (TSB 18-NA-383) that has caused progressive structural corrosion and water intrusion underneath the cab carpets near vehicle electrical routing since 2024. The certified GM technician explicitly identified GM Technical Service Bulletin #18-NA-383 as the governing bulletin for this exact issue. The technician’s diagnostic notes state word-for-word: "...i inspected the truck and the rear window is leaking i can see water stains on the window and the head liner has a big water stain. the floor is not rotted out but the rear of the rockers and the cab corners are rotting and bubbling under the paint." This proves the structural rot is being caused from the inside out by a factory defect, not environmental road salt. I have a duplicate large packet that I sent including +15 dated photos to GM corporate/legal back in August.

Filed Sep 6, 2026 · Body, Electrical · CA

Rear windows water leak. May caue electrical issues and mold in the cab

Filed Aug 24, 2026 · Body · NY

Paint delaminating from front fenders. No outside influence to cause it.

Filed Jun 8, 2026 · Body · 38,000 miles · KY

The contact owns a 2020 Chevrolet Silverado 1500. The contact stated that while vehicle was parked, water was leaking inside the rear interior of the cab. The dealer was notified of the failure, and the vehicle was serviced but the failure persisted. The manufacturer was notified of the failure. The failure mileage was approximately 38,000.

Filed Jun 1, 2026 · Body · CA

Component/System That Failed: The rear sliding window assembly leaked water into the cabin due to a manufacturing defect in the urethane seal and third brake light area. The window has been replaced and no longer leaks, but the water caused lasting damage to the headliner with trapped moisture. Components are available for inspection. Safety/Health Risk: The leak saturated the headliner, creating a serious risk of mold growth. My pregnant wife and unborn baby could be exposed to mold spores. Water intrusion also risks slippery floors, fogging, and potential electrical issues. Dealer Confirmation: Folsom Chevrolet confirmed the leak, replaced the window, and recommended full headliner replacement due to staining and mold risk. This is covered in GM TSB 18-NA-383. Manufacturer Awareness: GM has known about this defect for years but denied full repair (Claim #9582-9999). Symptoms: No warning lights. Leak first noticed in September 2025 after rains began. Due to dry California summer, it went unnoticed earlier, even though the defect likely started while the vehicle was still within the 3-year warranty period (mileage was over 36k when noticed). Additional Info: This is a known workmanship defect unrelated to mileage. A coworker has had the same issue twice on his 2025 Silverado. I paid $492.79 for the window + $144.50 diagnostic. GM offered only $1,250 in points and refused better resolution for the $3,100 headliner repair.

Filed Aug 2, 2025 · Airbags, Body · MI

Rear window is leaking onto the carpet beneath it creating mold and could allow water to enter the SRS module. Currently i have a tray blocking that water but without that the SRS system could be affected by the water entering the cabin through the rear window.

Filed Jul 28, 2025 · Body · WI

The Rear Window leaks when it rains on the truck. I brought it back to the GM Chevy dealer and they applied a sealant. it immediately leaked right after. the truck now smells musty and im assuming there is mold growth. it has been at the dealership for the past two weeks while they try to figure it out

Filed Mar 13, 2025 · Body · 40,000 miles · IL

The contact owns a 2020 Chevrolet Silverado 1500. The contact stated while the vehicle was parked inside the garage, he noticed a crack on the frame and there was water running back into the interior of the cabin and the backrest of the seat. There were no warning lights illuminated. On a separate occasion, the contact experienced water entering the cabin while it was raining due to the frame cracks. The contact contacted the water doctors and provided a diagnosis of frame crack in multiple locations, allowing water to enter the cabin of the vehicle and underneath the spoiler. The local dealer was contacted; however, the vehicle was not repaired because it was not under recall. The manufacturer was made aware of the failure. The failure mileage was approximately 40,000.

Filed Feb 26, 2025 · Body, Engine · MN

Lifter failure in the motor ALso, leaking in back window

Filed Feb 19, 2025 · Body · TN

My 2020 Chevrolet Silverado rear window leaks causing mold on headliner and carpeting and if running electric defrost during rain it makes a sizzling noise afraid of electrical issues as well if not correct and the mold makes the interior environment unsafe for breathing