The ice maker in my previous fridge made a very similar noise. Its was the unit cycling between make ice & done making ice. The "wand" that determines how much ice was in the storage tray had slipped a cog and was causing the unit to cycle. I moved the cog end up a notch and it then worked fine. That was until I opened the fridge one day and the "magic wand" was haywire again and the ice maker was well on its way to filling the entire fridge with ice cubes.
BTW - after 28 years the old fridge finally gave up. My new unit DOES NOT have an auto ice maker.