As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING 100-HOUR INSPECTION, COMPRESSION ON CYLINDERS 2 AND 4 LOW. REMOVED CYLINDERS. BROKEN AND MISSING PIECES OF RING. OIL SAMPLE SENT OUT. OVERHAUL FACILITY SAYS TAPPET DAMAGE. INSPECTED SAME AND FOUND NR 1 CYLINDER EXHAUST TAPPET WITH HEAVY DAMAGE. ENGINE SENT OUT FOR REPAIR.