As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OPERATORS WERE NOTIFIED AIRCRAFT'S ENGINE CONTAINED A PISTON PIN FROM THE BATCH LISTED IN LYC SB 527C. AIRCRAFT WAS REMOVED FROM SERVICE AND ALL CYLINDERS REMOVED TO VISUALLY INSPECT FOR BATCH NR 17328. CYLINDER NR 5 REVEALED BROKEN PIN. NUMERS WERE NOT CLEARLY VISIBLE, SO ALL PINS WERE CHANGED WITH NEW PINS DIRECT FROM LYCOMING.