As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER 162.0 HOURS OF OPERATION SMOH THE RIGHT ENGINE OIL TEMPERATURE WAS REPORTED TO STILL BE 20 TO 30 DEGREES HIGHER THAN LEFT ENGINE AND IN WARMER AIR TEMPERATURES THE COWL FLAP NEEDED TO BE OPENED TO KEEP IN THE GREEN. DURING TROUBLESHOOTING IT WAS DISCOVERED THAT THE VERNATHERM OIL CONTROL VALVE SPRING AND PLUNGER STUD HAD FAILED AT RETAINING NUT DRIFT PIN LOCATION. A NEW REPLACEMENT VALVE WAS INSTALLED RESULTING IN SATISFACTORY OIL TEMPERATURE.