As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS IN CRUISE, WHEN PILOT NOTICE MANIFOLD GO DOWN AND OIL COMING OUT OF ENGINE. 1) ON INSPECTION NR 4 CYLINDER HAD NO COMPRESSION. 2) PISTON HAD BROKEN RINGS TOP TWO PISTON WAS MELTED DOWN SIDE FROM CYLINDER GASES WHERE THE HING WHERE BROKEN.