As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB, THE NR 2 ENGINE BEGAN MAKING A POPPING NOISE AND THE MANIFOLD AND BMEP READINGS WERE WIDELY FLUCTUATING. CREW NOTICED A SLIGHT DROP IN THE ENGINE OIL LEVEL ON THE NR 2 ENGINE. ELECTED TO PERFORM A PRECAUTIONARY SHUTDOWN ON THE NR 2 ENGINE. ON INSPECTION OF THE ENGINE, DICOVERED THE NR 1 CYLINDER WAS CRACKED.