Banging is pipes, grinding is the auger.

If your ice maker is banging, it’s usually water hammer in the line. If it’s grinding, you’re looking at the auger motor or gears.

That loud bang when the ice maker fills is almost always water hammer—the water valve snaps shut and the pressure wave slams against the pipe. It’s common in refrigerators with long or poorly secured water lines. First fix: check the water line isn’t rattling against the back of the fridge or your cabinets. Zip-tie it down. If that doesn’t help, the real fix is a water hammer arrester on the supply line