As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER NORMAL FLIGHT AND ON TURN-AROUND, ENGINE ON POWER CHECK RAN VERY ROUGH AND WOULD NOT RESPOND NORMALLY TO THROTTLE ADVANCE. FOUND NR 5 CYLINDER WITH ONE BROKEN (INTAKE) PUSH ROD AND EXHAUST PUSH ROD BENT. ENGINE SHOP ADVISED VALVE STEMS STUCK. 15W50 AEROSHELL WAS IN USE AT THIS TIME.