As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE OIL TEMPERATURE CLIMBED TO 120 DEGREES C FOR UP TO 20 MINUTES IN FLIGHT. PERFORMED FUNCTIONAL CHECKS OF ENGINE OIL TEMPERATURE INDICATION SYSTEM AND TEMP BULB. BOTH FUNCTION PROPERLY PERFORMED TEMPERATURE REGULATING VALVE FUNCTIONAL TEST. VALVE FAILED TO CLOSE AND DETERMINED TO BE UNSERVICEABLE.