As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE PILOT REPORTED AN INTERMITTENT (POPPING) SOUND DURING ALL PHASES OF OPERATION. MAINTENANCE INVESTIGATION REVEALED A CRACK AND BLOWN EXHAUST GASKET ON NR 3 CYLINDER EXHAUST SEGMENT. THE CRACK EXTENDED AROUND MOST OF THE FLANGE, AND WAS CREEPING UP THE STUB APPROXIMATELY 1 INCH. THE SEGMENT WAS WELD REPAIRED AND REINSTALLED.