Car Air Conditioner Leaking Water Inside

Car Air Conditioner Leaking Water Inside

One common sign that your vehicle’s air conditioning system is due for service is when you notice the leaking of water from the vehicle. This can be from under the front of the car or inside on the passenger side. So why is water leaking inside the vehicle?

Air conditioners can leak into the vehicle due to blocks, damage, or low refrigerant. While some of these blockages or leaks can be fixed, anything else is likely going to require a visit to the nearest vehicle AC specialist.

I’ll explain the common causes of water leaking into your vehicle. I’ll also show you how to diagnose exactly what is going on as well as fixes that you can do to stop the leaking. If you have certain issues with the system like a leak you can’t find, it’s time to take the vehicle to a mechanic.

Check For Blockages

Car Air Conditioner Leaking Water Inside

Blockages of parts in the air conditioning system can cause water to leak inside your vehicle. These can occur at junction points, joins, or in the hoses of the system.

The first place to check is the evaporator. A clogged evaporator happens due to an accumulation of dirt or debris. The evaporator can generally be found on the passenger side of the vehicle, accessed through the glovebox.

If you look between the dashboard and the firewall you should see a metal object that looks very similar to the radiator. It may even have fans on it. Try removing the evaporator and clearing any obvious foreign objects from the intake.

The AC system will have a condensation drainage pipe or hose that can get blocked. Sometimes just referred to as an AC drain tube, you want to find the main exhaust for your AC and check the hose leading from it.

A blocked drain keeps the water from draining outside your vehicle. The only place it has left is to drain down the AC vents into the cabin or leak through the footwells. Manipulating hoses in several directions can help loosen debris which will then wash out. 

Depending on the vehicle it will be in different locations. You want to start by tracing from the AC system and this is sometimes easier to do from under the vehicle. The drain hose is usually located at the rear of the engine on the passenger side near the firewall.

Dirty or blocked air filters are also a common area that you should check if you notice water in the cabin. The job of an air filter is to prevent dirt, dust, and moisture from getting into the AC system.

However, filters themselves need to be checked and cleaned out to keep them functioning. You should have your car’s air conditioning checked and serviced regularly to keep the air filters clean. This is relatively straightforward and can be done by yourself.

Blocked filters may cause the system to operate poorly, causing excess water to overflow into the cabin.

Check For Leaks

Car Air Conditioner Leaking Water Inside

Another common cause of internal leaking of water is damaged seals. The plastic or rubber seals in your system will wear over time and start to leak. Finding these leaks can be tricky and even harder to seal, depending on how awkward of a place the leak is in.

There are specialty dyes and tools that can help you find leaks. If you’re not comfortable with using these tools, your best bet is to take your vehicle to a professional.

Look For Damaged Parts

The evaporator is also susceptible to corrosion. This is particularly the case if you notice rust damage on other parts of the vehicle. 

In colder climates, the road is salted and you want to keep salt away from your vehicle. Washing the vehicles down, particularly the underside, is a good way to prevent this from happening. 

Any leaks into the AC system introduce a high possibility of corrosion taking place. If you notice your system is performing poorly or leaking refrigerant, consider also that it is likely there could be some corrosion happening as well.

The condensation drain hose also has a habit of coming loose. Due to its location under the car, sometimes it can be hit by road debris and disconnect. Another common cause is blockages causing pressure which makes the pipe become unseated.

Check under the evaporator as this is one of the most common places of disconnect of the condensation drain.

Other Factors To Keep In Mind

If you find you are having an issue with excessive water leaking into the cabin it is vital you clean it up. Make sure to dry out your carpet and remove any floor mats to clean thoroughly. 

If the cabin is continually wet or damp, this can cause mold and mildew to grow. Not only will this result in serious health problems, but it also will have a terrible stench that will be very hard to get rid of.

Your vehicle’s AC is required to be a closed, pressurized system. This means it needs a certain amount of refrigerant to continue working. When the refrigerant level of your car’s air conditioning system becomes low, this starts to compromise the AC system.

Lower pressure will cause the coils of the evaporator to freeze. Not only will this cause your air conditioning to stop working but will also cause the drain pan to overflow and leak water.

Condensation can lead to excess water droplets around the AC components. When it’s too cold outside the coils could freeze and cause the system to leak water. Extremely hot or humid days can cause the same issue.

If this happens once or twice this shouldn’t be a cause for concern. However, if the system leaks water every time you use it then it is time to see an expert.

Gui Hadlich

Hey there! I'm Gui. To be honest, I'm not really that interested in cars. But what I'm really, really not interest in is spending lots of money fixing my car up. Thankfully, I have a father-in-law who's obsessed with cars and a brother getting a PhD in internal combustion engines, so I get to learn about fixing cars. And with Fixing Engines, I hope to help you save a lot of money and take good care of your cars.

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