DIAGNOSIS The print head carriage is hitting an obstruction or the carriage rail is dry. The noise is metal on plastic.
FIX Unplug the printer. Open the cover. Manually move the print head left and right along the rail. Feel for resistance. Clean the silver metal rail with a lint-free cloth dampened with a little water. Do not use oil.
IF THAT DIDN'T WORK A small piece of plastic inside may have broken off and is in the carriage path. Inspect for debris.
HEADS UP If the grinding continues after cleaning, stop using it. A worn carriage motor will destroy the mechanism.