5 ways water gets into your car when it rains
Your car is meant to protect you from the rain, not let it in. A leaking car can damage your interior and leave you soaked. So what can you do?
Identifying the exact cause of water intrusion is crucial, but easier said than done. Let’s look at all the possible points of leakage so you can stop guessing, solve the problem, and finally dry out your car.
Why diagnosing a leak is not easy
In many cases, diagnosing the root cause of a leak in your car is never easy. This is because the entry point for water intrusion is often hidden by various interior trims and panels. Therefore, this type of leak is only discovered if the moisture penetrates through adjacent coatings.
Moreover, leaking water always follows gravity and reaches the lowest possible point inside the vehicle, which usually includes the floor or trunk. In fact, in many cases, this type of leak is little different from a wet floor mat, which is only visible after a car wash or driving in a downpour.
A leak, whether large or small, is first diagnosed by identifying its source in a specific part of the vehicle’s interior. To do this, you will need to carefully inspect the vehicle’s windows, doors, and headliner.
What kind of damage can a water leak cause?
A large water leak can cause significant damage to the interior of your vehicle. Likewise, even a minor, uncorrected leak can cause a lot of problems over time. In the worst case scenario, water leaks can leave unsightly stains in your car and cause a constant musty smell. But in more extreme cases, mold growth can also be a very bothersome problem.
Many people don’t realize that water leaks in their car can cause a variety of electrical problems. When water gets into outlets, such as your vehicle’s fuse box or multifunction door switches, it can lead to future corrosion.
This corrosion most commonly manifests as excess resistance, affecting the functionality of certain circuits. Finally, if you park your car overnight in sub-freezing temperatures, you can expect to see frost on the inside of your windshield.
Common Causes of Water Getting Into Your Car
Water can get into your car for a variety of reasons, some of which are more likely than others. Still, it can be helpful to be aware of each of these potential issues when trying to solve the situation at hand.
Below are some of the most common sources of water in your vehicle:
1) Leaking Sunroof
If your car has a sunroof, it’s best to start by looking for the offending leak. Sunroofs and sunroofs are notorious for developing leaks over time, causing some serious chaos in the process.
How to check: Nearly every vehicle with a sunroof has built-in drain pipes. These pipes are located under the roofline of the vehicle, close to the sunroof itself, and if these pipes get clogged, water can leak into the interior of the vehicle.
When you open your car’s sunroof, you should be able to see the openings of these drain pipes. Check these openings carefully to see if they are draining properly or if rainwater is pooling instead.
How to fix the problem
Using a rubber-tipped blower nozzle, you can direct the airflow from a nearby compressor into one of the above drain pipes. You should do this until all blockages are completely cleared.
2) Windshield Seals
Another common cause of cabin leaks is damaged or corroded windshield seals. These rubber seals generally prevent water from entering through the edges of your vehicle’s windshield and usually last for years without any issues. However, a leak in this seal can cause problems and lead to a serious leak.
Here’s how to check for it
Windshield seal leaks are usually relatively easy to detect. If such a leak occurs along the top edge of your car’s windshield, you’ll likely see a wet headliner.
In contrast, if the leak is along the side or bottom edge of the windshield, you’ll usually see a wet dashboard.
How to fix the problem
The only way to completely and safely repair a windshield seal leak is to remove the vehicle’s windshield and have a qualified person reinstall a new seal. Products intended to renew such seals are rarely effective and are no substitute for a proper repair. Tip: When replacing your windshield, replace your squeaky wipers, too.
3) Window Seals
Similar to the windshield seal discussed above, each individual window in your vehicle has its own seal. Over time, these seals can become brittle and fall off piece by piece. Additionally, they can cause increased wind noise while driving, especially at high speeds. When this happens, your vehicle’s windows will lose a significant amount of their sealing ability. This condition often worsens over time, making it a very frustrating problem.
Here’s how to check for this
The presence of a window seal leak can be detected in just a few minutes using a garden hose. Carefully spray the suspect window seal from the outside before turning off the hose and checking for signs of water intrusion.
How to fix the problem
The only solution to a window seal leak is to replace the affected window seal yourself. Individual window seals can be ordered from almost any accessory manufacturer and installed in an afternoon.
4) Door Membrane/Seals
No matter the door type, a vehicle’s doors are also common sources of interior water leaks. A door’s first line of defense against water ingress is the door seal itself. The specialty weather strip prevents excess water from seeping into problem areas.
Likewise, vehicle doors also feature specialty membranes that allow any intrusive water to leak harmlessly through drain holes, to the ground below.
How to Confirm
Carefully study your vehicle’s doors after a period of rain. Water leaking in, or around the outer edge of a vehicle’s door is a sure sign of door seal issues.
Along the same lines, water running into a vehicle’s floorboard from behind the driver’s side or passenger side door panel is indicative of a leaking door membrane.
How to Fix
Like any other automotive weather strip, door seals can become compromised with age, requiring replacement to remedy any concerns over leakage.
5) Overflowing Evaporator Core Box
While this doesn’t require rain for it to occur, the evaporator core box, which is part of your car’s air conditioning system, can sometimes be a source of water leaks inside the vehicle cabin.
The most common reason for an overflowing evaporator core box is a clogged drain tube. If it becomes clogged with debris, the water can back up and overflow into the cabin.
How to Confirm
If you notice water pooling on the passenger side floor, especially after using the air conditioning, it could be a sign of an overflowing evaporator core box. You might also detect a musty smell coming from the air vents or a water sloshing sound.
How to Fix
Locate the AC drain tube under the car, usually near the firewall on the passenger side. Clear any visible debris from the opening of the tube.
Use compressed air or a thin, flexible wire to carefully clear any blockages inside the tube. If the problem continues, you may need to have a professional inspect and clean the entire evaporator core box and drain system.
