As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A 200-HOUR INSPECTION ALL CYLINDERS OF LT ENGINE PASSED A DIFFERENTIAL COMPRESSION TEST. CLOSER INSPECTION OF CLYLINDER ASSYS REVEALED CRACKS BETWEEN COOLING FINS OF SEVERAL CYLINDERS IN THE EXHAUST PORT AREA. NOTE: CRACKS ORIGINATING IN THIS AREA ARE NOT CHECKED DURING COMPRESSION TEST AND WILL LEAD TO CYLINDER HEAD SEPARATION IN 100 HOURS OR LESS. SUSPECT FATIGUE/SHOCK COOLING.