What was found
DURING CLIMB OUT, LAVATORY SMOKE MESSAGE. AFTER 10 SECONDS MESSAGE EXTINGUISHED. RETURNED FOR LANDING. LAVATORY SMOKE OPS CHECKED GOOD IAW TASK 26-14-00-700-801-A. TROUBLESHOT ODOR IAW FIM 21-20-00-810-803-A. OIL FOUND IN NR 2 ENGINE FAN CASE. R & R NR 2 ENGINE CARBON SEAL ASSEMBLY IAW RRMM 72-25-25-000-801. OPERATIONS CHECK & LEAK CHECKED GOOD. COMPLIED WITH ETN72-034 ODOR EVENT WORK CARD. OPS CHECKED FAILED. R & R NR 2 ENGINE IAW WORK CARD 71-000-00 ODOR GONE.