The answer to 'system upgrade making noise' is that a new HVAC system upgrade can sometimes make unusual noises due to a variety of potential issues. Common causes include improperly installed components, loose parts, airflow problems, or issues with the new equipment itself. Symptoms may include grinding, squealing, banging, or other loud noises coming from the indoor or outdoor units.
In many cases, these noises can be resolved by a qualified HVAC technician who can diagnose the problem and make the necessary adjustments or repairs. Attempting DIY troubleshooting is generally not recommended, as improperly servicing new HVAC equipment could void the warranty or lead to further damage. It's best to contact a professional HVAC contractor to inspect the system and provide a solution.