1. A bad or worn out drive belt. 2. A bad or damaged a/c clutch. 3. A bad or locked up a/c compressor.
If it's a creaking noise then it is most likely that your compressor is broken.
Your central air conditioner may make a loud noise when it comes on. This is because it may have a leak somewhere in the system.
Loud noise is not a good description. If its a loud squeal turn the air conditioner or defroster off. If the squeals goes away the compressor or the clutch for the air conditioner compressor is locked up.
Your air conditioner may be making a loud squealing noise because the AC compressor, which helps cool the air, could be malfunctioning. This could be causing the noise you are hearing.
Possible reasons for an air conditioner to make a loud noise include a malfunctioning fan motor, loose or damaged parts, clogged air filters, or issues with the compressor.
It is the alternator....
When an air conditioner makes a loud noise when turning off, it could be due to the sudden release of built-up pressure in the system. This can cause components to vibrate or move, creating the noise. Regular maintenance and checking for loose parts can help reduce the noise.
The fuel in the cylinders exploding
Your air conditioner may be making a loud buzzing noise due to a faulty fan motor, loose parts, or debris stuck in the unit. It is important to have a professional inspect and repair the issue to prevent further damage.
When lighting strikes it causes a cavity or vacuum in the air the loud noise is caused by the vacuum collapsing. as an example popping a plastic bag cause the same effect.
A little kid in the trunk with a hammer
Wheel bearing