What Causes Water Leakage in a Car?

[DelMarley]

Water leakage in a car mainly includes door leaks, sunroof leaks, and trunk water accumulation. Below are the relevant explanations: 1. Door leaks: Usually caused by aging window waterproof strips or clogged door drainage holes. Door leaks can result in water seeping out from the door trim panels, and in severe cases, water may accumulate under the cabin carpet. 2. Sunroof leaks: In most cases, this is caused by clogged sunroof drainage holes. Sunroof leaks can lead to wet headliner panels, and in severe cases, water may even "pour" from the sunroof into the cabin. 3. Trunk water accumulation: Generally caused by poor sealing of the trunk weatherstrip or tail light seals.

[MacAlan]

Water leakage in cars is quite common, especially after rain or car washes. I've encountered it several times and found the main issue lies with the sunroof. Leaves and mud can easily clog the sunroof drainage holes, causing water to seep into the car through gaps when it can't drain properly. Another problem is aging door seals—if they don't seal tightly, water can seep down the door panels and under the floor mats. Last time, my passenger side had standing water, and it turned out the AC drain hose had come loose, letting all the condensation leak into the cabin. If the windshield has been replaced, poor sealant application can also cause leaks. Trunk leaks are often due to deformed seals or faulty drain plugs. Untreated leaks can lead to mold and mildew, which is a nightmare—so it's best to regularly clean drainage holes, especially before the rainy season.

[LukeDella]

Finding water leaks in your car can be really frustrating. The most common issue is a clogged sunroof drain. The drain tubes are quite narrow, and things like tree seeds or cigarette butts can easily block them, causing water to overflow from the sunroof rails. Another critical point is the door seals. After five or six years, the rubber can harden and deform, leading to leaks when the door doesn’t close tightly enough. Air conditioning drainage problems are the most hidden—if the tube is clogged or detached, the passenger side floor often ends up wet. Aging or cracked sealant along the body welds can also let water seep in, especially in older cars. Additionally, damaged waterproof membranes around the window regulators allow water to pour directly into the door during car washes. My advice is to dry any wet spots with a towel immediately, then focus on inspecting these areas to avoid major issues like electrical shorts later on.

[VanAiden]

After washing the car last time, I found a pool of water under the driver's seat. Upon inspection, it turned out to be caused by the sunroof. The drainage holes were completely clogged with sand and mud, forcing the water to pour into the car. The door seal strips are equally important, as frequent opening and closing can cause deformation and leaks. The most surprising was the air conditioning system leaking—when the drain pipe got blocked, water flowed directly into the passenger footwell. Cracks in the windshield edge sealant are also a common cause. To fix it, first remove the accumulated water, then use an air gun to clear the drainage holes, which is quite effective. If the seal strips are worn out, you can buy new ones online for just a few dozen bucks. Regular checks on these areas can prevent a lot of trouble.