Water Leaking Outside or Inside of the Car
Water Outside the Car
Water leaking from under the car can be normal, especially on hot days when you’ve been cranking the A/C at full blast. Car A/C systems are actually designed to allow water to drain out of your vehicle. The system cools the cabin by pulling humidity from the air, and that moisture needs a place to go! Technically speaking, the A/C’s evaporator core condenses the humidity (turns it into a liquid). The liquid then exits the car onto the pavement via the evaporator drain.
While a drip or two is normal, a puddle is not. Stop by for a Courtesy Check and some peace of mind if you’re worried about water leaks that are increasing in volume or frequency, or ones that aren’t water leaks at all! Your car relies on a variety of vital fluids, all of which could leak and jeopardize your engine’s performance and vehicle safety.
Water leaking inside your car, on the other hand, is a surefire sign that (a) something is wrong or (b) your toddler dropped a sippy cup. No backseat snackers? It could be the car A/C leaking water on the floor (which we’ll go into deeper detail about), or it could be a non-A/C related issue.
For example, a poorly installed windshield or aging sunroof could allow water into the cabin. Excessive corrosion is another culprit, as it may cause tiny holes to form in your car’s body panels. And have you been in a car accident or fender-bender lately? The seams in your car’s body panels can break open and allow water to trickle in.
The timing of the leak can also tip you off as to whether it’s A/C-related. If you notice water pooling inside your car during wet and rainy conditions, investigate the areas mentioned above. Conversely, if the A/C is the source, water will likely show up on hot and sunny days when you use it the most.
Common Causes of Car A/C Leaks
1. Clogged Evaporator Drain
As we explained above, condensation and excess water leave your car through an evaporator drain. This is good. We want the water to flow out of your car through the evaporator drain. Sometimes, though, this drain can get blocked by dirt or debris. Like water in a clogged sink, the condensation from your A/C can back up. Once the evaporator core overflows, the moisture will make its way to the A/C vents, eventually turning into those annoying puddles of water you keep finding in your cabin.
It’s crucial to unclog the drain as soon as possible. If excess water remains in the evaporator core too long, it can damage electronic A/C components like the resistor, which controls fan speed or the blower motor, which powers the entire system! But your average grocery store drain cleaner can’t fix a clogged car A/C (and please don’t try it). You’ll want to come to Firestone Complete Auto Care.
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2. Faulty Seals
If plastic or rubber seals in your A/C system fail, water can seep out of the system and into your vehicle cabin. If this is the case, you’ll probably notice the water pooling up under the passenger side floor mats.
3. Leaking Evaporator Core
An evaporator core looks similar to a radiator—almost like a big grate. It’s possible for leaves or other organic material to reach the evaporator through the air intake vents. As this material breaks down, it becomes corrosive and can cause your evaporator core to rust, allowing water to leak.
If you notice a musty smell coming from the vents when you initially blast the A/C, you’re probably getting a whiff of those rotting leaves in your evaporator core. If this is the problem, the evaporator will need replacing.
Cleaning an A/C Water Leak
Once your car A/C issue is diagnosed and repaired, make sure to clean up the water in the cabin and dry out your floor mats. Mold and mildew thrive in humid conditions, and can create both a foul smell and a variety of health concerns for you and your passengers.
With spring upon us and even hotter months to come, reliable car A/C is crucial. A fresh and comfortable cabin makes all the difference on summer drives to your favorite getaways.