How to Quiet a Noisy Car AC Compressor-15 Working Processes

For many drivers, summertime means turning the air conditioning on and cooling off in their cars. But if your car’s air conditioner compressor is loud, it can be very distracting, not to mention irritating.

The worst thing about a noisy car AC is having to listen to it instead of being able to enjoy the music you’re playing or the conversation you’re having with your passengers. It can be especially distracting if the sound is very loud, as it can make it hard to concentrate.

Additionally, it can make for a rather uncomfortable ride, as the constant noise can be grating on your ears!

Noise is the most impertinent of all forms of interruption. It is not only an interruption, but also a disruption of thought.” -Arthur Schopenhauer

So, instead of dealing with the embarrassment or just abstaining from using the AC during your journey, why take the time to figure out what’s causing the noise, so you can get back to enjoying a pleasant trip with your car AC?

This article will discuss how to quiet a noisy car ac compressor.

Related: How to Quiet a Noisy Refrigerator Compressor: 10 Proven Ways

How to Quiet a Noisy Car AC Compressor
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How to Quiet a Noisy Car AC Compressor-15 Working Process

15 Ways to Quiet a Noisy Car AC Compressor

5 Process to Quiet a Noisy Car AC Compressor

How to Quiet a Noisy Car AC Compressor
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How to Quiet a Noisy Car AC Compressor

The most common noises we hear from an AC compressor are humming, rattling, and squealing noises.

Humming noises are generally a signal of loose components or erratic belt-and-pulley operation.

Rattling sounds point out worn-out bearings in the motor or a worn-out bearing plate and need quick attention if you want the AC compressor to last.

Lastly, squealing noises result from a broken belt that requires replacement for a sure-fire remedy.

Related: Best Car Sound Deadeners: Top 10 Materials

1. Quite Whining/Squealing Noise

This common sound is made by a car AC compressor and is usually caused by worn-out bearings or pulleys.

Replacing these bearing parts should fix the issue. Alternatively, you can also lubricate these components with appropriate lubricants to resolve the problem.

Fixing Worn-out Bearings Noise

  • You will need to remove the bearing from its housing to fix worn-out bearings in your car AC compressor.
  • Once you have removed the bearing, use a wire brush to clean off any dirt and debris that may be stuck on it.
  • After doing so, apply a liberal amount of quality lubrication appropriate for the bearing type, then reinstall and tighten the bearing into its housing.

This should resolve any issues with noise caused by worn-out bearings.

Fixing Worn-out pulley Sound

A worn-out pulley is a part of the car AC compressor that has become worn down due to age, wear-and-tear, or overuse.

  • To fix this issue, you will first need to remove the old pulley and inspect it for any visible signs of damage or wear.
  • If no signs are present, lubricate the pulley and bolt to reduce friction and noise.
  • Once the appropriate lubricant has been added by you, you can reinstall the new pulley and tighten everything back up.

This should resolve any issues with noise caused by a worn-out pulley.

2. Quite Rattling/Clanking Noise

This sound usually indicates loose parts within the compressor, such as broken belts or screws that vibrate inside the unit.

To fix this, you’ll need to remove the AC compressor and identify any faulty pieces before replacing them with fixed parts. Otherwise, you may have to replace the unit if it’s beyond repair.

Fixing Broken Belts Sound

Sometimes, a Car AC compressor rattling noise is made by a broken belt. A broken belt is a component of the AC compressor that has become worn or cracked due to time and/or excessive use.

  • To fix this, you’ll need to open up the unit and carefully inspect all exposed parts.
  • Any broken or worn-down belts should be replaced with new components and tightened accordingly.
  • To reduce friction and noise, you may also need to add lubrication to any affected areas.

Once you’ve completed these steps, your AC compressor should be free of rattling or clanking sounds!

Fixing Worn-down Screws Noise

Screws can become loose over time due to frequent use or out of place with vibration.

  • To fix this, if necessary, you’ll need to inspect the screws and ensure they are tightly fastened before tightening them using a screwdriver.
  • You may also have to replace any stripped, worn-down screws with new ones.
  • Additionally, you can add thread-locking adhesive to each screw hole to ensure they stay secure over time.

With these simple steps, your screws should be good as new!

3. Quite Grinding Noise

Car AC compressor grinding noise could mean one of its components has become jammed or stuck due to wear and tear. Before making any changes, properly identify what part of the compressor is at fault so that you can repair it and not end up replacing the entire unit.

My buddy, John, had been listening to a grinding sound from the air conditioning compressor in his vehicle for a few weeks last summer. I reassured him it probably wasn’t anything major but cautioned him to get it fixed before the difficulty became more serious.

But John was confident that he could fix it himself. So he watched a few videos on YouTube and researched how to repair the compressor before gathering the necessary tools and supplies. (He had soundproofed the coffee grinder noise earlier.)

He popped open the hood and started taking apart the AC system, slowly attempting to diagnose what was wrong with it. But despite his best efforts, nothing seemed to make a difference in fixing the grinding noise.

John was so enraged that he chucked his tools and marched off. He phoned me with the expectation that I could work out the problem where he had failed.

Sadly, John had damaged his AC unit.

How to fix: You’ll need to check the drive pulleys, belts and even the crankshaft for any jamming or sticks caused by broken parts.

If the problem is identified, then you may need to replace the part or upgrade it with a new one. If the grinding sound persists, then it’s likely that your AC compressor needs to be replaced as a whole.

4. Quite Hissing Noise

This noise usually indicates a refrigerant leak within the compressor, which can be dangerous.

The reason for a refrigerant leak is typically either an issue with the compressor gasket or a small crack in the compressor housing. If left unchecked, the leak could cause major issues, as refrigerant leaks can be hazardous to breathe in.

It’s always recommended that this type of repair be handled by a trusted mechanic, as they will have the required tools and know-how to get the job done properly.

  • To fix this, you’ll need to identify the exact source of the leak and patch it up with a special sealant to fix such leaks before refilling the refrigerant.
  • You may need to use a refrigerant leak detector to locate the leak.
  • After the leak is fixed, you’ll need to charge the system with refrigerant and test it to ensure it’s running properly.

5. Quite Knocking/Clicking Noise

The loose or worn-out fan belt is the most common cause of knocking/clicking noise from a car’s AC compressor.

The fan belt connects the compressor to the engine and drives it, so when the belt is not tight enough, this causes vibration and sometimes a knocking noise.

  • To solve this problem, you should ensure the fan belt is properly tightened and adjusted. Replace it if necessary.
  • Additionally, adding a dampening pad to your AC system can help reduce some excess noise, as this improves the airflow by dampening any sound frequencies transferred into the cabin from outside.

Related; How to Block High Frequency Sounds: 3 Free & 8 Premium Methods

How to Quiet A Noisy Car AC Compressor

  1. Tightening Loose Parts: Regularly inspect and tighten any loose parts in the AC system, which will help reduce vibrations as you drive. This should include fan belts, hoses, mounting bolts, and pulley components.
  2. Replacing Damaged Parts: Replace any cracked, frayed, or worn-out parts with new ones, as these are the most likely cause of the noise.
  3. Using a Dampening Pad: A dampening pad effectively reduces sound from your car AC compressor by dampening incoming sound frequencies before they enter the car cabin.
  4. Putting a Felt Cover on the Compressor: Adding a felt or rubber cover over the compressor can help minimize noise from excess vibrations.
  5. Lubricating the Compressor: Add oil or lubricant to the compressor to help reduce friction, which may also reduce noise.
  6. Installing Soundproof Insulation: Installing a layer of soundproof insulation within the engine bay and around other nearby components can also help reduce vibrations and sound frequency transferred from outside to inside the car.
  7. Replacing Your AC Compressor with a Quieter Model: If all else fails and you are still plagued by too much noise, you can replace your compressor with a quieter model. These should be designed specifically to reduce sound frequencies entering the car cabin. #8 Consulting with a Professional Mechanic: For larger and more complicated repairs, you may need to call a professional mechanic to help identify the root cause of your AC compressor noise and provide the best solution.
  8. Replace the Compressor Clutch Bearing
  9. Check Compressor Clutch Engagement
  10. Inspect and Lubricate the Compressor Belt
  11. Inspect and Clean Condenser and Evaporator Fins
  12. Check Refrigerant Leaks
  13. Seal Refrigerant Lines
  14. Add a Vibration Dampener to the Compressor
  15. Install Extra Insulation Around the Compressor Unit
  16. Disassemble and Clean All Moving Parts of the AC System

To determine what’s causing the noise from your car’s AC compressor, check to see if any components are missing or damaged. Some common culprits include loose bolts or screws, cracked belts, hoses, or worn-out bearings.

If you find any of these troubles and know your way around the engine, swapping these components out is an easy fix that won’t take too much time or money.

However, suppose you’re not comfortable inspecting the engine yourself. In that case, it’s best to take your vehicle to a professional to get a proper diagnosis and repair.

How to Maintain a Noisy Car AC Compressor

  1. Always keep the compressor clean and debris-free, as dirt build-up can reduce efficiency and lead to noise.
  2. If any damaged or faulty parts are noted (such as belts, hoses, etc.), repair or replace them as soon as possible.
  3. Make sure to use quality-grade motor oil and coolants, which should be regularly changed or flushed by the vehicle’s manufacturer’s maintenance schedule.
  4. Check for bolts and mounting hardware that could have loosened over time, tightening them as necessary for best performance.
  5. Look for potential duct openings that can lead to noise leakage from the compressor’s interior into the car’s cabin, patching them up with soundproofing materials if needed.
  6. Inspect all mounting points of your AC system once a month for signs of wear and tear. Then, make necessary repairs ASAP for optimum efficiency and noise reduction when running your AC compressor.
  7. Minimize the amount of hot air entering your car by using sun shades, tinting windows, and parking in the shade whenever possible. This will reduce the need for your compressor to work as hard to cool down the cabin quickly.

Is a Noisy Car AC Compressor Dangerous?

A noisy car AC compressor is not necessarily dangerous. While loud noises coming from the compressor can be irritating and possibly indicative of an underlying problem, it is typically not a risk for you or other passengers as long as it is properly maintained and any possible issues are addressed.

However, if a noisy car AC compressor isn’t addressed and maintained for some time, then certain risks can arise. Therefore, it’s important to know when to address any noisy sound your AC compressor might be making to prevent potential safety concerns.

When it comes to a noisy car AC compressor, the key signs you should look out for are: strange smells emanating from inside your car; rattling noises that won’t go away; visible coolant leaks; and changes in your air conditioning system’s cooling performance. If any of these warning signs occur, you should have your system immediately inspected by a trained technician. They should be able to diagnose any underlying issues and guide you to the best solutions for repairing your car’s AC compressor.

In terms of how to repair a noisy car AC compressor, the best thing you can do is let a professional handle it.

The process typically involves replacing the entire compressor assembly and flushing out any fluids or coolant. Then, depending on the cause of the initial noise, diagnostics may be needed to assess any other components that could be causing an issue.

After completing these steps, your AC system should be as good as new and make minimal noise.

Estimated Cost to Repair or Replace a Noisy Car AC Compressor: 

The cost to repair or replace a noisy car AC compressor can vary depending on various factors, including the make and model of the vehicle, the type of component that needs to be fixed or replaced, and the labor costs of the technician performing the repair.

In general, however, you can expect to pay between $150 and $1,000 for parts and labor.


So, we have discussed how to quiet a noisy car ac compressor at home.

There are many possible causes of noisy car ac compressors, and some may be easier to address than others. Some common causes of car AC problems, such as faulty fan belts, leaking refrigerant, and electrical wiring issues, can all be addressed by simple maintenance and repairs.

It is recommended to consult a trusted mechanic to get the best solution for your particular problem.

FAQs about quieting a noisy car ac compressor

Q 1: Can you drive a car without the AC compressor working?

Answer: Yes, you can drive your car without an AC compressor. However, doing so will reduce the efficiency of the vehicle’s air conditioning system and may lead to other issues related to its cooling system. 

Q 2: How can I tell if my car’s AC compressor is bad?

Answer: A few signs of a faulty AC compressor include loud noise coming from the compressor when in use, a lack of cold air produced by the car’s ventilation system, and leaking fluid from the unit.

Q 3: Why is my brand-new AC compressor so loud?

Answer: A new AC compressor may be loud due to several issues, including being overfilled with refrigerant, not being properly installed, or having old components such as fan belts or other parts that need to be replaced. Consulting a trusted mechanic for more information is recommended.

Q 4: Can you drive with a noisy AC compressor?

Answer: While it depends on the severity of the noise and how loud it is, driving with a noisy AC compressor is not recommended and may be dangerous, as doing so will reduce the efficiency of the vehicle’s air conditioning system. It is best to have any signs of a faulty AC compressor inspected by a trusted mechanic as soon as possible.

Q 5: What is the average lifespan of a car AC compressor?

Answer: The average lifespan of a car AC compressor varies, depending on the make and model, but averages around 10-12 years. It is important to have the unit regularly serviced to ensure it is functioning properly.

Q 6: Can a bad AC compressor damage engine?

Answer: A bad AC compressor can damage other components of a vehicle’s engine, particularly if it is leaking refrigerant or oil. This can cause the engine to overheat and ultimately lead to further damage. To prevent this damage important to have the AC compressor inspected and serviced as soon as any signs of trouble are noticed.

Q 7: Can overcharging car AC damage the compressor?

Answer: Yes, overcharging the car AC can damage the compressor, as too much refrigerant can cause the pressure and temperature within the system to rise to dangerous levels and cause components such as hoses, seals, and valves to fail. It is important to have a qualified auto technician inspect and service your car’s AC unit to ensure it has an appropriate amount of refrigerant.

Q 8: Why is replacing the car AC compressor so expensive?

Answer: Replacing a car AC compressor can be expensive due to the labor-intensive process of removing and installing the compressor, the cost of parts, and the cost of refrigerant. Additionally, compressors are designed with specialized components that must match up with certain models making it more expensive to replace them.

Q 9: Why does my AC sound like a jet engine?

Answer: This sound could be caused by a few things. It could be due to the compressor losing pressure, which would cause the compressor to vibrate and make a loud noise. It could also be the result of restriction on either the high side or low side of the system, causing it to overwork and make a loud noise. Lastly, it could be due to other defects in the system, such as faulty bearings or worn pulleys.

Q 10: How do you get rid of AC sound?

Answer: To reduce or eliminate AC sound, you should have a qualified auto technician inspect the AC system and diagnose the problem. Depending on the root cause of the sound, repairs such as replacing a faulty bearing, installing a muffler, lubricating moving parts, or even replacing components such as the compressor or condenser could be necessary to get rid of the noise.

About the author

Dipa Paul is a Home Improvement Blogger 🏠 Sharing DIY tips, product revs, & renovation stories 💡 15 yrs exp. 🔧Key strengths: creativity, problem-solving 🔥 Unique selling point: cost-effective solutions 💬 Let's build something beautiful together!

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