As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ROUTINE INSPECTION ON TCM FACTORY REMANUFACTURED TSIO520R (TIME 352.1 HOURS), CYLINDERS NR 1 AND NR 2 HAVE EXHAUST VALVE LEAKING. UPON CYLINDER REMOVAL AND HYDRAULIC LIFTER INSPECTION, REVEALED SPALLED LIFTERS IN NR 1 INTAKE AND EXHAUST POSTION.