As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED ON PREFLIGHT ENGINE RUN, THE MAP GAUGE INDICATED A 4" SPLIT AND THE LEFT ENGINE PRODUCED SMOKE. THE PILOT RETURNED TO THE APRON AND NOTED OIL LEAKING FROM COWLING. INSPECTION REVEALED THE LEFT ENGINE NR 2 CYLINDER EHXAUST PUSH ROD TUBE WAS BENT DUE TO THE VALVE STICKING CLOSED. THE DISPLACED PUSH ROD TUBE ALLOWED OIL TO LEAK FROM THE ENGINE. THE CYLINDER WAS REPLACED.