What Causes Water Leakage Above the Car Door?

[Oscar]

Reasons for water leakage above the car door: The door seal strip is not tightly sealed, causing water leakage; The drainage outlet at the bottom of the door is blocked, preventing water from draining out; The waterproof membrane inside the door is damaged, allowing water to flow directly onto the door sill trim and then onto the floor mat. Below are detailed solutions: Door seal strip not tightly sealed: If the seal strip is severely damaged or deformed, it needs to be replaced with a new one. If the exact location of the damage cannot be identified, adjust the door inward slightly to ensure tighter contact between the door seal strip and the door, making it harder for water to leak in. Blocked drainage outlet at the bottom of the door: Open the silicone strip at the bottom of the door to reveal a square-shaped drainage outlet. If the car hasn't been cleaned for a long time, mud and debris may accumulate. Use a flathead screwdriver to clear the blocked debris, allowing water to drain out and solving the leakage issue. Damaged waterproof membrane inside the door: First, sprinkle some water on the window, then open the door to check for any signs of water leakage. Use a T-20 spline, T-30 spline, and a flathead screwdriver to remove the door trim panel of the leaking door. Inside, you will see a plastic film—this waterproof membrane is adhered to the door panel with sealant. Dust ingress can cause the sealant to lose its adhesive properties, allowing water to seep through the gaps onto the door sill and eventually into the car. In such cases, the waterproof membrane needs to be replaced.