As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EXHAUST VALVE GUIDE LEAKING OIL. LOSS OF COMPRESSION. FOUND POOLING OF EXCESS OIL IN ROCKER BOX CAVITY AND SIGNS OF EXHAUST BLOW-BY ON EXHAUST VALVE SPRINGS. THIS IS THE 4TH VALVE GUIDE TO EXIBIT EXCESSIVE WEAR PROBLEM. THE CYLINDER WAS INSTALLED AS FACTORY NEW.