As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE NOISE DURING START-UP AND SHUT DOWN. REMOVED AND DISASSEMBLED MO5, 4, AND 3. FOUND COVER AND DEFLECTOR BROKEN AND RUBBING ON MO4 TURBINE DISC. THIS IS 2ND TIME THIS ENGINE SERIAL NUMBER HAS HAD A COVER AND DEFLECTOR BROKEN. SUBMITTER SUGGESTS A DIFFERENT STYLE COVER AND DEFLECTOR ABLE TO WITHSTAND ENGINE HEAT AND NORMAL VIBRATION LEVELS.