As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 3 ENGINE VIBRATES WHEN THRUST IS SET BETWEEN 53 TO 56 PERCENT N1. OIL TEMP ROSE TO 120 AND EGT CLIMBED TO 410. AT ALL OTHER THRUST SETTINGS, ENGINE OIL TEMP RUNS 20 DEGREES HOTTER. PERFORMED BORESCOPE REF M-40 51190, NO DEFECTS NOTED. PERFORMED ENGINE VIBRATION SURVEY, CHECKED WITHIN LIMITS REF M-40 51192.