As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THERMOSTAT VERY NEAR FAILING WITH POSSIBLE SEVERE ENGINE DAMAGE RESULTING. SEAT RETAINING NUT VERY LOOSE ON STEM. NUT WAS 'JUMPED' 2 THREADS. THIS PART NUMBER AND SERIAL NUMBER SUBJECT TO LYC BULLETIN SIBC AND SI'S 1, 2, AND 3. SUBMITTER STATED THIS INSPECTION AND REWORK HAD NOT BEEN COMPLIED WITH.