As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON DISASSEMBLY FOR ITS FIRST OVERHAUL, DAMAGE WAS FOUND ON THE LEFT HAND CRANKCASE HALF TO THREE THRU STUD BORE LOCATIONS. THE DAMAGE APPEARS TO BE A GOUGE WITH DISPLACED METAL JUST UNDER THE CYLINDER PADS JUST INSIDE THE THRU STUD BORES. SIMILAR DAMAGE ON OTHER ENGINES WAS PREVIOUSLY REPORTED. IN ADDITION, ONE OF THE THRU STUDS HAS DAMAGE UNDER THE THREADED PORTION ON THE SHOULDER OF THE THRU STUD.