Diagnosis
The evaporator plate (the freezing coil) is scraping against the plastic housing or ice has built up around its mechanism.
How to Fix It
Perform a full defrost and inspection. Unplug, remove all ice, and let it sit for 2 hours. Remove the ice basket and the thin plastic cover over the evaporator. Check for any visible ice chunks or debris caught in the gears.
If That Didn't Work
The gear motor that twists the evaporator plate might be failing. If the noise is a consistent metallic grind, the motor bearings are likely worn.
Heads Up
This noise often starts if you let ice over-accumulate in the basket, which strains the harvest mechanism. Keep the ice level below the max line.