What Causes Water Leakage While Driving?
4 Answers
Reasons for water leakage while driving: 1. Sunroof leakage, mainly caused by aging seals or clogged drainage holes, which can be resolved by cleaning the drainage holes or replacing the seals; 2. Door leakage, due to faulty or aged door waterproof seals, it is recommended to directly replace the seals; 3. Trunk leakage, caused by poor sealing of the trunk seal or tail light seal. If water accumulation is found in the spare tire compartment of the trunk, it should be taken seriously, and repairs should be done as soon as possible. Solutions for car water leakage issues are generally very simple and low-cost, but it is crucial to address leakage problems promptly. If water seepage is left unattended, it can lead to mold growth in the interior and potential risks of electrical short circuits.
Last time my car had a water leak, after checking for a long time, I found out the sunroof drain holes were clogged, causing rainwater to back up and flood the interior. Actually, other common causes include aging and deformed door seals—during heavy rain, water seeps in through the door gaps. If the AC drain tube is blocked, condensation water will leak onto the passenger-side carpet when the AC is on. And if the windshield sealant cracks, you’ll see water streaks flowing down the A-pillar during car washes. Once, a friend’s car leaked because rust had perforated the seams of the underbody panels, which was a real hassle to fix. I recommend regularly cleaning the sunroof drainage channels, checking the elasticity of door seals during car washes, and addressing leaks immediately to avoid mold growth inside the car—that would be a nightmare.
When repairing cars, I often encounter water leakage issues in several areas. First, the sealant around the windshield ages and cracks, allowing rainwater to seep in through the gaps. Second, the roof drainage channels get clogged with leaves and mud, causing water to overflow into the cabin. Blocked door drainage holes due to sediment buildup can also lead to water backing up. The most troublesome issue is rusted-through body weld points, where water seeps up from the chassis. Once, a customer's BMW had a water leak, and it turned out to be caused by a deformed trunk seal. A reminder to everyone: try to avoid parking under trees, regularly use an air gun to clear drainage holes, and immediately investigate if the carpets feel damp—otherwise, waterlogged wiring can easily cause short circuits.
Car water leaks generally occur in five areas: clogged sunroof drainage tubes causing water to backflow into the headliner; damaged door waterproof membranes allowing rainwater to seep into door panels; detached AC drain pipes leading to condensation leaks onto floor mats; failed windshield seals permitting water ingress into the dashboard; rusted-through floor panels enabling water accumulation to seep from the chassis. I recommend first checking which part of the carpet is wet to identify the leak source. During repairs, prioritize cleaning sunroof drainage channels and testing door seal integrity, promptly replacing aged rubber seals. Regularly avoid parking under trees to prevent leaf blockages, and remember to clean drainage holes during car washes.
