Is the water line kinked?
If the refrigerator has been recently installed or moved, check to make sure the water line has not kinked. A kinked water line can cause several issues, but can also cause a chattering or rapid clicking sound.
Is the refrigerator level?
It is important to ensure the refrigerator is level. A properly leveled refrigerator will help with the overall proper operation of the refrigerator. Check to make sure the floor under the refrigerator is level. If the floor is not level shims may need to be used to properly level the refrigerator. Please refer to your Owner's Manual or Installation Instructions for specific leveling information for your refrigerator.