As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI OUT, LAV-C SMOKE ALARM SOUNDED ACCOMPANIED BY AN OILY ODOR IN CABIN. STARTED REMAINING ENGINE AND RAN ALL THREE PACKS. ODOR DISSIPATED AND FLIGHT DEPARTED. DURING CLIMB ODOR RETURNED AND REMAINED BETWEEN DOOR 2 AND 3. RETURNED TO SEA AND LANDED WITHOUT INCIDENT. MAINTENANCE DEFERRED THE NR 3 PACK AND REPLACED NR 1 AND NR 2 COALESCERS. OPERATIONAL CHECK NORMAL.