What Causes Water Leakage Under the Front Passenger Seat?

[ArianaMarie]

Reasons for water leakage under the front passenger seat: 1. The condensation pipe above the front passenger's left foot gets cold, causing water droplets to form upon contact with air. 2. The air conditioning drain pipe is too short or has become loose and aged, causing the pipe to bend and obstruct drainage, leading to water spilling inside the car. 3. Clogged sunroof drain holes or guide pipes. 4. Aging sealing strips around the air conditioning unit or car doors. Solutions: 1. Clear the drainage holes on both sides of the engine compartment. 2. Unclog the sunroof drainage holes. 3. Secure the air conditioning pipe near the air filter. 4. Clear the drainage holes below the car doors. 5. Replace the sealing strips around the air conditioning unit and car doors.

[DeHope]

Sigh, the other day my car had a wet passenger footwell, and after checking for a long time, I found out the AC drain hose had come loose. This is a pretty common issue—when the AC is on, condensation water is supposed to drain out from under the chassis, but if the hose is misaligned, it just pours into the car. An experienced driver told me that aging, deformed rubber hoses or getting accidentally kicked loose can cause this. To check, crawl under and feel if the hose connection is loose, and also check if the carpet has a musty smell. Make sure to fix it promptly, as accumulated water can damage the wiring. Some cars also have sunroof drain hoses running through here, but AC-related issues are the most common.

[MacJameson]

Last time I helped a friend fix a similar water leak, it turned out to be cracked windshield sealant. During heavy rain, water would flow along the A-pillar into the front passenger floor, making it nearly impossible to trace the source. Nowadays many cars use double-sided tape to secure windshields, which can come loose over time. Another often overlooked issue: clogged door drain holes can cause rainwater to seep in through the sill plate gaps. The detection method is simple - slowly pour water along the upper edge of the windshield and observe where it leaks. Regular inspection of aging rubber components is crucial, don't wait until accumulated water causes rust damage.

[DelVivian]

My newly purchased car had water accumulation in the passenger side, which turned out to be caused by the installation of a dashcam! During the wiring process, the sealing ring on the firewall was pushed out, allowing car wash water to pour in through this hole. It's crucial to choose a reliable shop for modifications. Also, be cautious about coolant leaks—the heater core is located behind the dashboard, and leaking fluid will have a sweet smell and be colored. If you notice water leakage, first lift the floor mat to check the amount of water. A small amount might be due to an air conditioning issue, but if there's about half a bucket's worth, it's likely an antifreeze leak, and you should get it fixed immediately.