As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI OUT, SMOKE BEGAN TO ENTER THE CABIN. AIRCRAFT TAXIED BACK TO THE GATE AND PASSENGERS DEPLANED THROUGH THE JETWAY. MAINTENANCE FOUND OIL LEAKAGE AT NR 3 BEARING COMPARTMENT ON NR 2 ENGINE. REMOVED AND REPLACED THE NR 2 ENGINE.