As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 OIL TEMP DROPS TO 45-50 DEGREES IN CLIMB WITH SAT OF -4 DEGREES C WITH LOW ALT SAT OF +15 DEGREES C IN CRUISE. NR 2 OIL TEMP IS 50-55 DEGREES C. RETURN TO FIELD. R & R ENGINE OIL TEMP BULB AND LEAK CHECKED, NO FIX. R & R NR 2 ENGINE OIL COOLER DIVERTER VALVE IAW 79-20-11. RAN ACFT, OPS CHECKED GOOD. OK FOR SERVICE.