The answer to 'central air making noise' is that there are several common causes for a noisy central air conditioning system, including worn bearings, loose parts, refrigerant issues, or airflow problems. Symptoms may include grinding, squealing, rattling, or banging noises coming from the outdoor condenser unit or indoor air handler.
In many cases, minor issues like a loose fan or duct can be fixed with some basic DIY troubleshooting and repairs. However, if the noise is coming from the compressor or other internal components, it's best to call in a professional HVAC technician to diagnose and repair the problem. Attempting to fix major issues yourself could make the problem worse or even damage the system.