Why Do I Hear Water In My Car: Causes And Solutions

You’re driving on the road, and suddenly, the water-sloshing sound catches your attention.Why do I hear water in my car?

What’s happening with your vehicle? This may confuse you a lot because you don’t know what to do.

In fact, cars making noise is one of the most popular issues that drivers have to face. There are many reasons that lead to this situation.

Depending on the position where you hear it, you’ll need the typical solution to fix it. Learn more about this in the next parts.

Why Do I Hear Water In My Car?

Why do I hear liquid sloshing in my car? Exterior causes include clogged AC drain, clogged windshield drain, worn out sunroof drain, and water in the side steps. Internal culprits are, low coolant, blown head gasket, and issues with the heater core.

It’s popularly described as the sloshing one, but many people also hear a gurgling or clicking noise.

Water Sloshing Sound In Car: Exterior Causes & Solutions

Why do I hear liquid sloshing in my car? Why do I hear water in my car? Let’s learn about the exterior causes first. 

Why Do I Hear Water In My Car

A Clogged AC Drain

When the air conditioner in your vehicle is turned on, condensation forms along the evaporator coil, then drips into a condensate drain pan and under the car.

This is the common one that makes sounds like sloshing. 

The evaporator condensate pan’s stagnant water can spill onto your vehicle’s floorboard and serve as the ideal environment for mold growth.  

You might hear the water sloshing sound in the car coming from behind the dashboard since moisture results in a blocked drain. This sound is more audible when turning and braking. 

Another sign is a damp floorboard; if the pan fills up with too much liquid, it may overflow into the vehicle’s interior.


Compressed air is the simplest way to unclog a condensate drain. Under your car, find the evaporator drain tube.

Blow compressed air into the tube opening. When there is no compressed air available, you can try placing a flexible wire into the tube hole to unclog the drain. 

When mending this, keep in mind to put on the glass and gloves since dirty, moldy water could leak out as soon as you push compressed air into the system.

And to get rid of any caked-on filth and grime in the drain, give it a good shake.

A Clogged Windshield Drain

When facing this situation, don’t ignore the windshield drain. It’s also one of the most popular exteriors that the mechanics diagnose when their customers say, “I can hear water in my car“.

This can originate from a clogged windshield drain in the cowl/firewall area.

When too much moisture builds up in the cowl region, it may leak inside the car. Its floorboard will rust from the inside if this occurs frequently. Damage to control units is also conceivable in the worst-case scenario.


In most cases, to access the top of the drains, you need to remove the plastic panel at the bottom of the windscreen.

A flexible cable, high-pressure air, and a water flush can then be used to clear the drains. 

Having your mechanic do it during the subsequent service would be better. The vehicle owner should do daily cleaning of the windscreen base to prevent debris from washing into the gutter below.

Worn Out Sunroof Drain

After a long time of use, dirt and particles may get into the drain holes. You will hear a sound if there is a worn-out rubber gasket on the sunroof. 

With such a status, the liquid will penetrate in your vehicle when you wash your vehicle or it rains.

Water can get stuck in these holes, and not all the liquid can drain out immediately, causing water sloshing in the car

This can also trigger liquid leaking on your headliner when you leave it for too long. Eventually, the water falls into the car’s interior, and stains will appear on your ceiling.


The quickest and most effective solution is replacing the drain with a new one. It only takes some bucks, or you can do it at home. It would be better to replace this part periodically to avoid unexpected damages.

Water In Side Steps

If you have just experienced a heavy rainstorm, going through an area with a storm or flood, moisture is easily stuck in the side steps and difficult to drain.

This can cause it to backflow into other internal components.

You may have to pay more to fix the problem with the car door sensor and another electrical system.


With side steps, it’s pretty easy to deal with. It would help if you had a blower/compressor to eliminate standing water. Otherwise, a large-capacity fan will also be helpful in this case.

Water Sloshing Sound In Car: Interior Causes & Solutions

Why does it sound like water in my car? It’s time to learn about the second main cause: the interior.

Interior Causes

How To Detect Interior Sloshing? 

How can I detect it when I hear sounds like water in my car? Usually, one will check the exterior factors first.

If you have inspected the four problems above but still can’t identify the problem, the interior causes can be to blame.

Low Coolant 

Low coolant levels might generate a sloshing sound from under the dashboard when the engine is operating. That is the common reason for the question: Why do I hear water when I start my car?.

The level of antifreeze in your vehicle determines the symptom of low coolant. Your antifreeze light will flash when the car witnesses a drop in coolant

The “Check Coolant” message might appear on the dashboard of some cars. Some of these peculiarities might be apparent if your coolant light is on.


Examine the amount of coolant in your vehicle. Pour coolant into the coolant reservoir until it reaches the recommended level. After a few weeks of driving, if the coolant level drops, there can be a cooling system leak.

A Blown Head Gasket 

When the seal between the engine block and cylinder head breaks, it causes a blown head gasket. Between these two engine regions, the head gasket seals the coolant route and other parts.

These channels are no longer sealed when the head gasket fails. This leads to oil leaks, coolant leaks, or gasses escaping from the combustion chamber.


It’ll require a sealant to fix a leaking head gasket. Only when a minor leak is present, which results in symptoms like overheating and coolant/antifreeze loss, is this possible.

Replacement is a must when symptoms are more severe, such as a large leak. As this is a complex issue, your vehicle will need to be checked and repaired by experts.

Issues With The Heater Core

The last one that triggers engine noises in the vehicle is the issue with the heater core. You could occasionally detect a liquid sloshing sound in your automobile’s radiator when you start the engine.

Its air bubbles in the coolant are the culprits behind this. These bubbles, together with trapped air, are pushed to the top of the fluid when the automobile is cranked up.

The mixture dissipates after being blasted out by the engine. Inside your cabin, the air bubbles are making some noise.

However, your heater core may malfunction if you still hear this noise after starting your car or see evidence like water droplets or puddles on the ground under your car after driving.


Because the heater core is a pretty important part, you will have to turn to the support of a professional mechanic.

This requires you to pay a few tens of dollars to several hundred dollars for the service center, but in return, the car’s performance will be guaranteed.

Wrapping Up

Why do I hear water in my car? You already have the answer to this! To sum up, we’ll take a look at the common causes that lead to this situation:

Exterior causes: 

  • Clogged AC drain
  • Clogged windshields drain
  • Worn out sunroof drain
  • The liquid in the side steps

Interior causes:

  • Low coolant
  • Blown head gasket
  • Issues with the heater core

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