As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AIRCRAFT EXPERIENCED SLIGHTLY ABOVE NORMAL CYLINDER HEAD TEMP ON NR 2 & 4 CYLINDER AFTER LEVEL OFF AT CRUISE ALTITUDE. VISUAL INSPECTION VERIFIED FAILED CYLINDER ASSEMBLY. ECI CONFIRMED THAT THIS UNIT WAS A NEW BARREL INSTALLED AT OVERHAUL. IT WAS A FIRST RUN CYLINDER.