The answer to 'tune-up making noise' is that a noisy HVAC tune-up can be caused by a few common issues, such as loose parts, worn bearings, or a problem with the blower motor. This can result in rattling, grinding, or other loud sounds coming from your HVAC system during or after the tune-up.
In most cases, these noises are a sign that something needs to be adjusted, repaired, or replaced. While some minor tune-up issues can be addressed with DIY troubleshooting, it's generally best to call in a professional HVAC technician to diagnose and fix the problem. They have the expertise and equipment to properly inspect your system and make any necessary repairs to get it running quietly and efficiently again.