How To Quiet A Noisy Car AC Compressor

How To Quiet A Noisy Car AC Compressor

A noisy AC compressor is a source of frustration. If you are thinking about how to quiet a noisy car AC compressor, then you are at the right place.

AC compressors can make noise due to worn-out bearings, loose connections, worn-out belts, and refrigerant leaks. There are many simple methods to quiet a noisy car AC compressor.

When I was in your situation, I researched deeply to find out how to quiet a noisy car AC compressor. Finally, I was able to find some methods which work perfectly. In this article, I will explain the reasons for the AC compressor noises and how to quiet your noisy car AC compressor.

Is It safe to Drive with A Noisy Car AC Compressor?

No. It is not safe to drive with a noisy car AC compressor. You do not know exactly what the reason for the noise is. So, we should find it. Bad AC compressors can result in increased engine load, overheating, and belt-related issues. Sometimes it can affect other important components such as the alternator.

How To Quiet a Noisy Car AC Compressor

Let’s move on to our topic: how to quiet a noisy car AC compressor. To reduce the sound of the AC compressor, first you should determine why the sound occurs.

Noise TypeCause
SquealingWorn-out bearings and pulley
RattlingLoose parts, vibrating screws, broken belt
GrindingJammed or stuck components
HissingRefrigerant leak
ClickingLoose or worn-out fan belt

Here are the 5 unusual noises that come from the AC compressor and how to quiet them.

Squealing Noise

Squealing noise comes from the AC compressor as it ages. This is due to worn-out bearings and the pulley.

How To Quiet The Squealing Noise of the Car AC Compressor?

To quiet this sound, first try lubricating the bearings.

  1. First, remove the bearing from the housing and clean it. You can use a wire brush to remove debris.
  2. Then apply some lubricants to the bearing.
  3. Reinstall the bearing and check for the squealing noise.

Note: If lubricating does not solve the issue, then you have to replace the worn-out bearings.

Rattling Noise

If a rattling noise comes from the AC compressor, it means some parts of the compressor are loose. It might be due to vibrating screws and a broken belt.

How To Quiet The Rattling Noise of the Car AC Compressor?

Serpentine belt of a car

Inspect the belt, which connects the AC compressor and the engine crankshaft. In newer vehicles, there is no separate belt for the AC compressor, and many components run on the common belt called the serpentine belt. If so, check it out. If the belt is damaged or worn out, you should replace it.

Important: Never lubricate belts as it causes them to slip.

Inspect the screws of the AC compressor and tighten them if they are loose. Replace them if you find damaged screws.

Grinding Noise

Grinding noise suggests a jammed or stuck component within the car’s AC compressor due to wear and tear.

How To Quiet the Grinding Noise Comes from the Car AC Compressor?

You should identify the problematic parts. Check the drive pulley, belts, and crankshaft for any jamming or sticking. If you find any problems with the belt pulley or the belt, replace them. If the crankshaft is jammed, try to repair it. You have to remove the entire engine from the vehicle to replace the crankshaft. Luckily, crankshaft problems are very rare.

If you are unable to find any culprits for the grinding noise, consider replacing the car’s AC compressor.

Hissing Noise

If there is a refrigerant leak in the compressor, it results in a hissing noise.

How To Quiet The Hissing Noise Comes from the Car AC Compressor?

You should have some technical knowledge to repair refrigerant leaks and prevent hissing noises.

Clicking Noise

A loose or worn-out fan belt is a common cause of clicking noises from a car’s AC compressor.

How To Quiet the Clicking Noise Comes from the Car AC Compressor?

Check the fan of the AC compressor.

If the fan is loose, tighten the bolt at the middle of the fan blades using a wrench.

How to Keep the AC Compressor Quiet?

Car AC compressor

Here are some tips to keep the AC compressor from making any frustrating noises.

Clean the Air Filters

Dirty and clogged air filters block the airflow and put additional strain on the AC compressor. This leads to various noises. Clean the air filters every 15,000 miles. Replace them according to the manufacturer’s recommendations. It will ensure optimal performance of the AC compressor.

Lubricate Moving Parts

We discussed above that low lubrication speeds up the wear of the components. The result of worn-out bearings is a squealing noise. Regular lubrication can reduce friction, noise, and wear on moving parts.

Monitor Refrigerant Levels

What happens if you run on low refrigerant levels? AC systems want to keep the ideal cooling temperature inside the car. So, when the refrigerant level is low, the compressor has to work harder to ensure proper cooling. You have to keep the refrigerant levels checked once every two years.


Why does my AC compressor shut off after 2-3 minutes?

Airflow over the evaporator must be sufficient to evaporate the refrigerant; otherwise, the compressor may overheat and the air conditioner will turn off early. Most airflow issues are caused by a clogged air duct register, a filthy air filter, or ductwork debris.

Can I drive with a seized AC compressor?

No, you cannot drive with a seized AC compressor. It puts extra strain on the engine and results in engine overheating. If you want to drive with a seized AC compressor, you should bypass the AC compressor with a serpentine belt.

How to bypass AC compressor pulley?

You can bypass the AC compressor pulley using a serpentine belt or the AC compressor bypass pulley.

Does antifreeze run through AC compressor?

No, antifreeze doesn’t go through the AC compressor. This fluid is only compressed by an AC compressor.


A noisy car AC compressor can be a major annoyance during your drive. Now you know how to quiet a noisy car AC compressor. However, if you’re not comfortable inspecting the engine yourself, it’s best to consult a professional mechanic.

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