As a car DIY’er with years of experience, I’ve seen my fair share of leaks, and let me tell you, water leaks inside a car are no joke.
They can cause all sorts of damage, from mold and mildew to electrical malfunctions.
In this blog post, I’m going to explain why your car might be leaking water inside and what you can do about it.
Why Is My Car Leaking Water Inside?
There are several reasons why your car might be leaking water inside. Here are the most common ones:
Clogged AC Drain
If your car has air conditioning, it has an AC drain that gets rid of the water that’s produced when the AC is running. If this drain gets clogged, the water can back up and leak inside the car.
You’ll usually notice this problem when you turn on the AC and water starts dripping from the dashboard.
Damaged or Missing Weatherstripping
Weatherstripping is the rubber seal around the doors and windows that keeps water out. If this seal is damaged or missing, water can seep inside the car.
You’ll usually notice this problem after it rains and the floorboards are wet.
Leaking Windshield or Window Seals
The seals around the windshield and windows can also wear out and start leaking.
You’ll usually notice this problem after it rains and water is dripping from the top of the windshield or windows.
Faulty Heater Core
The heater core is the part of the heating system that warms up the air that comes out of the vents. If it’s damaged, water can leak inside the car.
You’ll usually notice this problem when you turn on the heat and water starts dripping from the dashboard.
Water Entering Through Sunroof Drains
If your car has a sunroof, it also has drains that get rid of the water that accumulates on the sunroof when it rains. If these drains get clogged, water can back up and leak inside the car.
You’ll usually notice this problem when you see water stains on the headliner or pillars.
Leaking Body Seams or Door Seals
The body of the car has seams where different panels come together. If these seams are not sealed properly, water can seep inside the car. The same is true for the seals around the doors.
You’ll usually notice this problem after it rains and water is dripping from the top of the door or the bottom of the door frame.
Condensation is the process by which water vapor in the air turns into liquid. This can happen inside the car when the air inside is cooler than the air outside. If you have a lot of condensation inside the car, it can start to feel like it’s raining.
You’ll usually notice this problem when the windows are foggy and the interior is damp.
Overflowing Windshield Washer Fluid Reservoir
The windshield washer fluid reservoir is the container that holds the fluid that sprays onto the windshield when you use the wipers. If this reservoir overflows, the excess fluid can leak inside the car.
You’ll usually notice this problem when you see wet spots on the floorboards.
How to Fix Water Leakage Inside a Car
Now that you know why your car might be leaking water inside, let’s talk about how to fix it. Here are some solutions you can try:
Cleaning the AC Drain
To clean the AC drain, locate the drain tube under the car and use a wire or a coat hanger to remove any debris that’s blocking it.
To replace weatherstripping, buy new stripping that fits your car and remove the old stripping. Clean the area where the new stripping will go, apply adhesive, and install the new stripping.
Fixing Leaks in Windshield or Window Seals
To fix leaks in the windshield or window seals, you’ll need to remove the old sealant, clean the area, and apply new sealant.
This can be a tricky job, so it’s best to leave it to the professionals.
Replacing the Heater Core
To replace the heater core, you’ll need to remove the dashboard and disconnect the heater hoses. Then you can remove the old heater core and install the new one.
This is a complex job that requires special tools and expertise, so it’s best to leave it to the professionals.
Clearing Sunroof Drains
To clear sunroof drains, locate the drains (usually near the corners of the sunroof) and use compressed air or a wire hanger to remove any debris that’s blocking them.
If you’re not comfortable doing any of the DIY solutions or they don’t work, it’s time to take your car to a professional mechanic. Here are some solutions they might recommend:
Replacing Damaged Seals
If your car has damaged seals, a mechanic can replace them with new ones.
Resealing Body Seams
If your car has leaking body seams, a mechanic can reseal them with new sealant.
Checking for Damage to the Body
If your car is leaking water inside, it’s possible that the body has been damaged in an accident. A mechanic can check for any damage and make repairs if necessary.
Cleaning Out the HVAC System
If your car has a lot of condensation buildup, a mechanic can clean out the HVAC system to remove any mold or mildew that’s causing the problem.
Water leaks inside a car can cause all sorts of damage and are not something to be taken lightly. If you notice any signs of water leakage, it’s important to act quickly to prevent further damage.
Use the solutions outlined in this blog post to try and fix the problem yourself, but if you’re not comfortable doing so or the DIY solutions don’t work, take your car to a professional mechanic.
With the right expertise and tools, they can quickly diagnose the problem and provide a solution to get you back on the road safely.