As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENGINE HAS A RUMBLING VIBRATION WHEN RUNNING. STARTER GENERATOR LUGS AND SURGES DURING START CYCLE. REMOVED AND REPLACED STARTER GENERATOR. WORK WAS DONE IRT 24-81-01. OPS AND LEAK CHECK GOOD. COMPLIED WITH CMM TASK 05-50-00 FOR UNSCHEDULED GENERATOR CHANGE. NO DEFECTS NOTED. RAN A/C MULTIPLE TIMES WITH NO VIBRATION.