As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PROBLEM ORIGINATED FROM A ROUGH RUNING ENGINE CAUSED BY BROKEN CYLINDER VALVE SPRINGS. CYLINDER WAS REMOVED FOR REPAIR AT THIS TIME SPALLED CAMSHAFT AND LIFTERS WERE OBSERVED NECESSITATING A COMPLETE ENGINE TEARDOWN WHICH EXPOSED THE ADDITIONAL PARTS WITH CORROSION ON THEM.