How does water enter the car when the sunroof drain is blocked?
2 Answers
When the sunroof water channel is full, water directly enters the headliner and usually seeps out from the A-pillar and C-pillar. Below is relevant information: 1. Air circulation: The car sunroof is installed on the roof, effectively facilitating air circulation inside the vehicle and increasing the intake of fresh air. Additionally, the sunroof can broaden the view and meet the needs of mobile photography and videography. Car sunroofs can be roughly categorized into: sliding-out type, built-in type, built-in flip-up type, panoramic type, and curtain type. 2. Ventilation method: The car sunroof changes the traditional ventilation mode. Wind blowing in forms an airflow that draws out the stale air inside the cabin. When the car is driving at high speed, air flows rapidly around the vehicle. When the sunroof is opened, a low-pressure area forms outside the car. Due to the difference in air pressure inside and outside the vehicle, the stale air inside the car is drawn out, achieving ventilation and keeping the cabin filled with fresh air.
The roof of my car got wet after the rain that day, and upon investigation, I found it was caused by a clogged sunroof drain. Rainwater falls into the drainage channels around the sunroof and normally flows out through the drain pipes at the four corners to the bottom of the car. However, if the pipes are clogged with leaves or dust, the water can't drain and accumulates in the channels. Once the channels are full, the water finds gaps to overflow, usually where the sunroof seal isn't tight enough, allowing water to seep into the car. Worse, the water might flow into the roof lining or down the A-pillars onto the floor mats, slowly soaking the interior. Over time, this can lead to mold, unpleasant odors, and even damage to electronic components. I recommend checking and cleaning the sunroof tracks every six months and using compressed air to clear the drain pipes. Now, I no longer worry about leaks, and my car stays much cleaner.
