As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT 3316, RT PROP OIL TEMP FLUCTUATING 100-160 DEGREES. AIR TURNBACK TO DTW. MAINTENANCE REMOVED AND REPLACED RT PGB TEMPERATURE BULB P/N 4053T73P01, S/N ON LEW5137. RAN ENGINES, ALL CHECK GOOD AT THIS TIME. ALL IAW SF340 AMM.