Man Putting Fingers in Ears

How To Fix A Vibrating And Noisy Car A/C Compressor

Nothing beats the comfort brought by your car’s air conditioner especially when it is hot outside. Well, you can only enjoy that if the AC is working. What if you turned on your AC and hot air greeted you instead? There is reason to worry when that happens. Definitely, you want to figure out where that hot air came from. Have you heard vibrations or any noise in your car’s A/C compressor? That can be the source of the problem.

The weird and unusual sounds you hear should be a cause of concern especially when you have not heard them before. It is a sign that something is wrong with the air conditioner. You should fix this noise right away before it gets into further damage. Here is how you can treat the problem depending on the type of noise made.


This can usually be heard when you turn on the A/C and should be taken as a sign that your A/C is beginning to show signs of failure. One of the reasons for buzzing noise is an overcharged system created by the fact that too much Freon may have been added to the system when you sent it out for servicing. You need to correct this issue quickly or else suffer the need to replace the entire A/C compressor when the problem worsens.

Loud Squealing

Squealing is common when the serpentine belt has a problem. This one is the most commonly reported noise for a car’s A/C compressor. Some will use belt dressing to diagnose the concern but it is best to spray a bottle of water into the belt. If the noise suddenly stops after doing so then you should send your car out for inspection. If the serpentine belt is old, it will need replacement.


Hissing noise is commonly heard when you turn the car off. This is actually a result of equalizing the pressure made by the A/C compressor as the Freon moves from high pressure to low pressure. This is a normal occurrence and should not be really taken as a bad sign.


This may not really be a common issue when compared to all other sounds mentioned but once the sound is produced constantly, you should take it as a sign that there are loose mounting bolts on the A/C compressor. You can simply look at the problem while the engine is running. All you need to do is tighten any loose mounting bolts and add a certain amount of thread-locking compound to resolve the issue.


When your car seems to produce a vibrating or rattling sound once it is turned on, you should make sure you have the A/C compressor checked at once or the problem can worsen. It can also be related to a serpentine belt that has reached its lifespan which needs replacement or it can be because of a worn out compressor clutch too. The clutch needs to be replaced every now and then.