As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL 310, THE NR 1 OIL TEMP NEEDLE INCREASED TO 130 CELSIUS. FOLLOWING A REDUCTION IN THRUST TO 1.5 EPR THE TEMP DROPPED BELOW 120. HOWEVER, THE NEEDLE CONTINUED TO FLUCTUATE AND GIVE ERRATIC READINGS. TEMP REMAINED BELOW 120. ALL OTHER INDICATIONS NORMAL. REPLACED OIL TEMP INDICATOR AND OIL TEMP BULB.