As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLIMBOUT OF MSP, THE NR 1 ENGINE OIL TEMPERATURE WAS FLUCTUATING AND SEEMED TO STABILIZE AT 170 DEGREES. THE FLIGHT RETURNED TO MSP LANDING WITHOUT INCIDENT. MAINTENANCE REPLACED THE OIL TEMPERATURE SENSOR, SYSTEM OPERATION APPEARED TO BE NORMAL. AIRCRAFT RETURNED TO SERVICE.