As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PERFORMANCE OF SB 388C, IT WAS FOUND THAT THE NR 4 CYLINDER EXHAUST VALVE TO GUIDE CLEARANCE MEASURED .031". THIS EXCEEDS THE MAXIMUM ALLOWABLE CLEARANCE OF .030". THIS ENGINE WAS OVERHAUL. THE TOTAL TIME SINCE NEW IS NOT BEING LISTED AS IT IS NOT KNOWN HOW LONG THIS CYLINDER OR EXHAUST VALVE HAVE BEEN ON THIS ENGINE. IT IS KNOWN THAT THE ENGINE WAS OVERHAULED 897.7 HOURS AGO AND THIS CYLINDER AND VALVE WERE INSTALLED AT THAT TIME. WHETHER THEY WERE NEW OR OVERHAULED AT THAT TIME IS NOT KNOWN.