What are the causes of water ingress on one side of the car cabin?
3 Answers
Water ingress into the car cabin can occur due to the following reasons: 1. Sealing issues: Improper alignment of the sunroof cover, such as uneven height or incorrect left-right gaps that do not meet the manufacturer's standards, can lead to poor sealing. Additionally, if the sunroof cover is not fully closed or left open, it can cause water leakage into the cabin ceiling. 2. Corrosion problems: After collision repairs to the car roof, if proper rustproofing is not done, severe corrosion of the roof panel or the edges of the sunroof frame can result in water leakage into the cabin ceiling. 3. Sunroof drainage system issues: The sunroof drainage system mainly consists of drainage channels, drainage pipes, and drain valves. The sunroof is not completely sealed, allowing some water to seep in, which flows into the drainage channels. While minor water seepage is normal, problems such as cracked drainage channels, detached, folded, broken, twisted, or poorly routed drainage pipes, or clogged drain valves can all lead to water leakage into the cabin ceiling.
I've encountered the issue of water leaking into the driver's side of my car quite a few times. There are several main reasons: aging door seals are the prime suspect – over time, the rubber hardens and cracks, allowing water from rain or car washes to seep in. Sunroof problems are also quite common; if the drainage tubes are clogged, water has nowhere to go and leaks into the cabin through gaps. Another issue is leaks in the air conditioning system, where loose seals in the pipes or evaporator can cause water to drip onto the floor. Accumulated water under the car body or deformed mudguards can also lead to water entering one side. Don’t forget improper repairs after accidents, where gaps might not be properly sealed. To fix it, first check the condition of the seals and clean the drainage holes. If the problem persists, don’t try to fix it yourself – take it to a professional shop for a safe inspection and repair. Remember to dry and check after each car wash to avoid bigger troubles.
As a car shop assistant, I've seen quite a few cases of water ingress on the driver's side: damaged seals are the most common issue, especially when the rubber around doors and windows wears out leaving large gaps; clogged sunroof drainage holes can cause water backflow; leaks from the AC evaporator or pipes are also major problems; high water pressure during car washes or rain may seep in through fenders or the undercarriage; improperly closed windows or loose seals can allow water to enter one side. Upon discovering water ingress, immediately check rubber seals and clean the drainage system—DIY fixes can save trouble but require careful attention. If the situation is severe, don't delay—get it repaired promptly to prevent internal electrical shorts that could compromise safe driving. Pay special attention to these areas during regular maintenance to reduce the likelihood of malfunctions.
