Gurgling Sound When AC Is On In Car – Causes & Fixes 2023

Do you know how your car’s air conditioning keeps the interior cool? In addition, it occasionally emits a gurgling sound, similar to boiling water. Although it’s not what you’d expect, don’t worry; it’s not a major concern most of the time.

The noise is due to trapped air. The gurgling arises from air bubbles in the heater core’s cooling system, sometimes signaling a blocked evaporator drain.

Let’s explore the cause and solutions for gurgling sounds when air conditioning is on in your car.

Why is the Car Making Gurgling Sound When AC Is On?

1. Trapped Air: 

Trapped air is one of the main causes of the gurgling sound coming from the AC system in your automobile. Imagine a cooling system filled with little air bubbles that create a distinctive gurgling sound as they move through it. This phenomenon frequently happens in the heater core, where trapped air bubbles can produce an auditory disturbance.

Trapped Air
Source: Jb tools

2. Condensation, Evaporation, and Movement:

Temperature changes, condensation, and evaporation interact to produce the gurgling sound you hear from your automobile’s air conditioning system. Let’s deconstruct it:

The air conditioning system cools the air inside your automobile, removing heat and humidity. It uses a refrigerant that absorbs heat by changing from a high-pressure gas to a low-pressure liquid. Air moisture transforms into water droplets on the evaporator coil when this refrigerant absorbs heat like dew developing on a cold glass.

Condensation, Evaporation, and Movement
Source: cars24

This water is meant to drip into a tray or a drain before leaving the car. However, when it’s extremely hot or humid, more water collects than can be swiftly drained away. Due to air movement and heat from the outside, the temperature in the tray changes as the AC system continues to run. The gathered water occasionally evaporates as a result of this. As a result, air pockets develop. These air pockets mix and flow through the drainage channels when additional water enters and exits the system.

The gurgling sound is produced by the movement of air pockets in the channels. Think of the gurgling sound that occurs when you pour water from a bottle because of the passage of air through the neck of the container. These air pockets produce similar sounds through your car’s air conditioning system channels. This sound may be more audible when the AC operates at full blast.

3. Clogged Evaporator Core Drain:

Another possible explanation for the gurgling noise is a blocked evaporator core drain. As the air cools, your AC system creates condensate, which is drained away to avoid water buildup. However, if the drain is blocked, water may build up and make a gurgling sound as it tries to exit.

Clogged Evaporator Core Drain
Source: Hvac

4. Air In The Coolant Or AC System: 

Air that has become trapped in the coolant or the AC system itself may be the cause of the gurgling sound. These peculiar noises can be produced when air develops air pockets when it combines with coolant or refrigerant. You may imagine the sound you hear as the coolant or refrigerant moves through the system and bumps into these air pockets.

How To Fix Gurgling Sound When AC Is On In Car?

After revealing the mysteries underlying the gurgling noise, let’s explore the fixes that can make your trip quieter and more comfortable:

1. Bleed The System:

Bleeding the system can frequently solve the problem if the reason is trapped air in the cooling system. It entails performing the bleeding method advised by the manufacturer to release the compressed air.

Bleed The System
Source: quora

2. Unclog The Evaporator Core Drain: 

If an obstructed evaporator core drain is to fault, it is crucial to remove the blockage. A specialist can remove the obstruction and guarantee appropriate drainage, minimizing water buildup and the gurgling sound.

3. Check For Leaks: 

A comprehensive leak check is necessary before addressing air in the cooling or air conditioning system. If any leaks are found, they need to be fixed, and the system needs to be properly drained and recharged to get rid of any air bubbles.

Check For Leaks
Source: blue devil products

4. Regular Maintenance: 

Preventive maintenance is the key to preventing gurgling sounds from your car’s AC system. Regularly inspecting and maintaining your air conditioning system can help avoid problems like trapped air or clogged drains in the first place.


What Is Gurgling Sound In AC Line?

A bubbling or gurgling sound is a prominent air conditioning warning sound. The cause of this can be a refrigerant leak. If a refrigerant leak in the line is not fixed, it can lead to major health problems like nausea, vomiting, and breathing problems.

Is The Gurgling Sound A Serious Problem? 

The gurgling sound rarely poses a serious threat. It frequently happens as a result of internal AC system natural activities. However, getting professional advice is essential if you detect other problems, such as leaks or a decline in cooling performance.

Is It Safe To Use the AC If I Hear The Gurgling Sound? 

It’s normally okay to turn on the air conditioner when you hear gurgling. However, a professional should examine the AC system if you detect any other unusual symptoms or if a diminished cooling performance accompanies the gurgling.


The next time you hear that mysterious gurgling sound when the air conditioner is on in your car, you’ll understand that it’s not simply some random noise but rather a signal from the cooling system. The causes may include trapped air, clogged drains, and air in the system, but there are workable remedies. You can guarantee a nice and quiet trip, free from the enigmatic melodies of gurgling air, by bleeding the system, unclogging drains, or seeking professional help.

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