The answer to 'mini split making noise' is that there could be several common causes, such as a problem with the compressor, fan motor, or refrigerant issues. Symptoms may include grinding, rattling, or buzzing noises coming from the outdoor or indoor units. Some solutions may involve tightening loose components, replacing worn parts, or adjusting the refrigerant charge, but these fixes often require the expertise of a professional HVAC technician.
In general, it's best to call a qualified HVAC specialist to diagnose and repair any unusual noises in your mini split system. Attempting DIY repairs on these complex systems can be dangerous and may void the manufacturer's warranty. A professional technician will have the proper tools, training, and expertise to safely identify and resolve the issue.