As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VERNATHERM VALVE WAS REMOVED FROM ENGINE, RETAINING NUT WAS FOUND LOOSE. THIS VERNATHERM DID NOT APPLY TO SB 518C BY SERIAL NUMBER. IT WAS INSPECTED DUE TO PREVIOUS REPORTS OF VERNATHERM FAILURES WHICH MET SB 518C CRITERIA. SUBMITTER STATED POOR DESIGN, RE-DESIGN PART.