As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 ENGINE TREND DATA SHOWS LOW PRESSURE ROTOR VIBRATION LEVELS TO BE TRENDING HIGHER THAN EXPECTED CURRENT LEVELS NEAR 1.5 UNITS. ACFT GROUNDED. ACCOMPLISHED ON BOARD FAN TRIM BALANCE ON NR 2 ENGINE IAW MM 71-00-00-750-808-F00. SWITCHED WEIGHT NR 2 FROM P11 TO P14, NR 3 FROM P13 TO P09, NR 5 FROM P14 TO P09, NR 6 FROM P12 TO P14.