You get into your car after a rainstorm or while running the A/C on a humid day and discover a damp or soaking wet carpet, usually on the passenger side. This mysterious indoor water leak is a common problem caused by a simple issue: a clogged drain tube.
For Singaporean drivers in Malaysia, where both heavy rain and high humidity are constants, this is a frequent complaint. This guide explains the two most common culprits and how they are professionally cleared. If your car has sprung an internal leak, MyMechanic can help diagnose the source.
Your car's air conditioning system works by passing warm, humid cabin air over a very cold coil called the evaporator (located behind the dashboard). This cools the air, and the moisture in the air condenses into water, just like on a cold drink can. This water collects in a tray and is supposed to exit the car through a rubber drain tube that pokes out through the firewall to the underside of the vehicle.
Over time, this dark, damp environment is a perfect breeding ground for mold and gunk. This gunk can form a blockage in the drain tube. With the drain blocked, the water tray fills up and overflows, spilling directly into the passenger footwell.
A technician will safely lift the car, locate the end of the drain tube underneath, and use a blast of compressed air to shoot back up the tube, dislodging the blockage. Alternatively, they may use a flexible plastic wire to gently ream it out.
If the leak only appears after it rains, the problem is likely your body drains.
A technician will locate the exit points of these drains (in the wheel wells or under the car) and use compressed air or a flexible trimmer line to clear the blockage from the bottom up, preventing debris from being pushed further in.
A wet carpet is more than just an annoyance; it can lead to mold and serious electrical damage. For Singaporean drivers in Malaysia, MyMechanic provides on-site diagnostics to determine the cause of water ingress, whether it's from the A/C or a clogged body drain, and advise on the proper fix.
MyMechanic Roadside Assistance
Available 24/7 — Every Day of the Year
A wet footwell is a simple plumbing problem. By understanding that your car has a network of drain tubes designed to manage water, you can quickly narrow down the cause based on when the leak occurs. For Singaporean drivers, keeping these drains clear is excellent preventative maintenance for dealing with Malaysia's tropical climate. When a blockage does occur, a quick and simple service from a professional like MyMechanic can solve the problem before it leads to bigger issues.
