Why Is Toyota Corolla Leaking Water On Driver Side Floor?

Floor water leaks are quite common, causing many Toyota Corolla drivers to ask questions all over the automotive forums. In this article, we will go together to explain the possible causes of your car leaking water.

If Toyota Corolla leaking water on driver side floor, you need to deal with it promptly because a lot of serious problems can cause it.

If water sits in the carpet for too long, mold can grow and cause odors. In particular, it will affect your health because many types of mold on cars have a very unpleasant smell.

So where does water come from? How to detect such problems? We’ve listed some of the most common problems below for you to have more useful information.

4 Reasons Toyota Corolla Leaking Water On Driver Side Floor

Other possible problems include corrosion of the pin connectors, windshield, roof windows, failure of the control computer system, sensor failure, rust, and high humidity inside the vehicle causing the windows of the vehicle to be damaged and get foggy, etc.

1. Windshield Is Leaking

The windshield is an important part to help us observe the vision on the car, shielding from rain, dust, or obstacles on the way.

Some of the reasons why cars leak water are due to bad windshield installation. Windshields can be installed improperly to the chassis or between connections that are not covered with strong glue or adhesive.

As a result, water can follow the gaps in the windshield and flow into the car. If your car is often wet when it rains, you should check the windshield and especially the joints and edges to prevent water from entering the car.

In addition, the quality of the windshield is also a factor you should consider because many drivers often replace them because of collisions with obstacles on the road.

Low-quality windshield replacement and unprofessional handling will also leave your car vulnerable to car water leak problems.

2. Water Leakage From Welds, Joints

Welds and joints are the second major cause of water leaks in your vehicle. Seams that are not properly welded at the factory, or seams damaged in a car accident, will often cause water leaks for no apparent reason.

Your car may have been in some kind of collision that caused the welds or joints on the car to break and create small gaps. When it rains, water will follow those small channels to enter your car.

If you find any cracks, you should fix them thoroughly by welding them or taking them to a repair shop because your car will often leak water every time it rains.

3. Leaking Water From The Sunroof

Does your car have a sunroof? Check the drain lines. The cause of water leakage can also come from installation, connections, or gaskets from the sunroof.

Manufacturers have ordered a built-in tray with four drains in each corner of the sunroof. Sometimes these drains get overflowed or clogged and will leak water into the vehicle.

Locating the drain hoses can take some time as they are often buried in the fenders and bodywork. In addition, poorly installed aftermarket accessories are another major cause of your car’s water leaks.

Anything from a sunroof to a roof rack system if not installed with the right adhesive and with the right connections will cause water leaks in the car.

4. The Air Conditioner Drainage System Is Clogged

As the air conditioner sucks the moisture out of the air in the passenger compartment, it accumulates a lot of water that must be drained out of the vehicle.

It is completely normal for water to fall from the drain of the air conditioner to the ground. However, if water flows back into the car and drips onto the floor, you need to fix it immediately to avoid mold.

Check the drain hose of the air conditioner or evaporator, it may be clogged or disconnected. Debris sucked into the evaporator from the outside will clog the drain hose.

A quick temporary fix for this problem is to blow compressed air into the drain hose located under the car, after which you will have to remove the evaporator and clean the residue.

Another cause is a leak from the heating core. Car heaters circulate coolant through the dashboard area to heat the car, and if the heater core leaks, water can drip onto the floor.


In general, there are several possible causes of water leakage from damaged door seals, glass screens, or deformations to clogged air conditioner drains or damaged heat exchangers.

If it’s the heater or the air conditioner’s fault, it will dry on its own when the weather is dry. You just need to leave the car in a well-ventilated place and don’t forget to leave the car door open. The sun will make your car dry and avoid the musty smell.

Finding out what’s causing the leak is the first thing you need to do. You need to see where the water enters the car, not just along with the dashboard or seams but also in the sunroof, etc.

You can test it by pouring water into the areas you feel suspicious about and watching to see if the water gets into the car.

Only by doing this can you tell if the crevices, welds, or door seals, and sunroof joints are damaged.

Moreover, what do you do when your car floor gets wet? Turn off the air cooler and use the blower to treat the wet area.

Next, you can get some desiccant products, such as baking soda, that you can leave inside the car behind each seat. This will work overtime to dry out your car’s cabin and reduce the chance of a moldy odor developing.

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