As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
2 ENGINE TREND DATA SHOWS A SUDDEN INCREASE IN LOW PRESSURE ROTOR VIBRATION LEVELS. DATA SCATTER INDICATES FAN LUBE AND HARDWARE INSPECTION REQUIRED. ACFT GROUNDED. ACCOMPLISHED FAN LUBE AND REPLACED ALL SHIMS AND SPACERS REF T/C 78472002 NR 2 ENGINE. ACCOMPLISHED TEST 7-VIBRATION SURVEY IAW TASK AMM 71-00-00-700-814-F00.