Car AC Compressor Making Noise-How to Fix

Car ac compressor making noise how to fix
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Noise in the air conditioner is expected since air movement in the air conditioner makes buzzing, humming, grinding, and whirring noise when starting. However, the loud noise from the air conditioner shows there is a problem with the unit.

The air conditioner works by cooling the car parts and environment when the car is moving. However, while the air conditioner is working, the compressor can start making uncomfortable noises to car users.

To correct some issues with the air conditioner that causes the noise, first identify the problems with the air conditioner and then fix them accordingly, following the instructions on how to handle the parts. The most common type of noise in the ac compressor is the rattling noise that occurs due to failures with the compressor, faulty pulley, fault belt, and issues with the idler pulley.

The article below shows the causes of the noises in the Car ac compressor, which are the faulty parts in the air conditioner. There are the steps to follow when fixing the noises from the air conditioner, frequently asked questions, and the conclusion, which summarizes the whole article.

Steps of loud troubleshooting noise from the Car ac compressor

car ac compressor making noise

Tools needed

1. Switch off the air conditioner in the car

Switch off the air conditioner for the fixing process to be more accessible. When switching off the parts, ensure you disconnect the air conditioner from the engine that provides power to run.

2. Check and remove the faulty parts

Remove faulty air conditioning parts like the condenser, compressor, and air filters and fix new features that do not make noise. Consider calling a technician to aid with the fixing process to prevent destroying the air conditioner.

3. Arrange the condenser coils in place

Arrange the condenser coils in the air conditioner by ensuring they are straight to avoid loud noise production in the air conditioner.

4. Tighten the loose wires

Tightly hook the loose wires and cables in the air conditioner so that when the air conditioner vibrates, they do not contact each other and make a loud noise that destroys the owner’s comfort.

5. Clean the dirty parts

Remove the dirty particles in the air filters by cleaning them, picking the debris, and wiping away dust using a piece of cloth. Consider using specific detergents when cleaning the dirty parts.

6. Add lubricants to the system

Lubricate the air conditioning system to prevent corrosion that causes the motor to make screeching sounds. Ensure you use the specific lubricants with the plan to avoid damaging them later.

Causes of noise in the Car ac compressor

1. Dirty particles in the ac compressor

The availability of dirty particles like dust, tree branches, leaves, and other debris may stick to the surface of the air conditioner.  The waste accumulates in the air conditioner blocking the air filters and producing rattling noises when exchanging air in and out of the house.

2. Old and loose screws

Old screws tend to unfix themselves from the parts they hold in the air conditioner hence becoming loose. The loose screws always make loud noises in the air conditioner when starting due to the vibrations of the air conditioner making the loose screws rattle. The sudden vibration every time the air conditioners turn on makes the screws loose after some time.

3. High air pressure in the air conditioner

High air pressure in the air conditioning system causes noise in the unit due to the explosions in the compressor when air moves into the air conditioner.

4. A leaking refrigerant

Leaking refrigerant in the air conditioner allows air to pass in and out of the conditioner contrary to normal operations. The sudden air movement causes some noise when the air conditioner is starting as it lowers the refrigerant level.

5. Free and loose air filters

When the air filters are loose, the air conditioner produces a loud noise when starting because the air passes through the air filters, and if there are some loose parts, the air will pass through these parts, producing some noise.

6. Poor capacitor battery

A capacitor has a battery that holds a charge to power the compressor and other parts in the air conditioner. Therefore if the battery is poor, it cannot store an amount that will power the air conditioner, producing loud noise as it strains to start due to lack of enough power.

7. Faulty electrical connectors

When starting, faulty electrical connectors like the signals and sockets may affect the air conditioner, producing loud noise since the connectors will keep switching off and on, making some noise. Deficient electrical components can cause some sparks when starting the air conditioner where noise accompanies these sparks.

8. Defective thermostats

Defective thermostats result from using the thermostat for a long time, making them poorly connected to the air conditioner. The loud noise after that results from the relay, which keeps sending power to the faulty thermostat.

9. Leaking duct in the air conditioner

When the air conditioner has leaking ducts, air will pass through the leaking ducts making the air conditioner loud.

10. Dirty air filters

Dirty air filters block the exit and entrance of air into the air conditioner, making the motor produce loud noise since air forces itself into the air conditioner, which comes with high pressure. The air conditioner’s force to create a path into the air conditioner makes noise in the air conditioner.

11. Insufficient lubrication in the motor

Some motors need lubrication more frequently for fast and easy running. Therefore, when such engines lack lubrication, it will produce noise at the start, making the air conditioner have loud noise if the lubrication process fails to occur.

12. Bad contractor

A contactor is a part of the air conditioner that regulates the connection between the air conditioning system and the power suppliers in a room. So when the contactor is faulty, it fails to perform its work by turning off or on the power supply. It forces the air conditioner to turn on the electricity itself, producing a loud noise.

13. Defective capacitor

A capacitor is a device in the air conditioning system that stores power for use by the air conditioner. Therefore, when the capacitor is loose or faulty, it prevents parts like the fan from switching on, causing noise due to friction.

Frequently asked questions:

  • Is it a must for a car to have an air conditioner?

When having a car, you need to ensure you have an air conditioner to help you cool the environment in the vehicle. The air conditioner helps reduce the high temperatures with most parts of the car overheating and provides a relaxed atmosphere for the driver and other people inside the vehicle. Therefore, ensure the air conditioner parts work correctly to maintain a comfortable environment.


The article above describes why the air conditioner makes loud noises and how to fix the problems. By reading the report carefully, you can identify the reasons for some noises in your air conditioner and how to solve them.

Always read the manufacturer’s instructions on the air conditioner before taking any action and maybe purchasing new parts for a replacement since the details differ according to the type of the air conditioner. In case of any difficulties when replacing the noise features in the air conditioner, consider calling a professional to help fix the problem.

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