What was found
(CAN) ON GOING REPORTS OF LAVATORY SMOKE DETECTOR ACTIVATION. PROBLEM APPEARS TO HAVE BEGUN ON JANUARY 17, 2007 WITH A PILOT REPORT OF THE NR 2 ENGINE WILL NOT START AFTER (3) ATTEMPTS AND THEN AN OIL LEAK. MAINTENANCE REPLACED THE ENGINE IGNITERS AND CLEANED THE RESIDUAL OIL. ENGINE WAS THEN STARTED SUCCESSFULLY AND RUN TO TROUBLESHOOT THE OIL LEAK. NO OIL LEAK COULD BE FOUND AND IT WAS SUSPECTED TO BE AS A RESULT OF THE NO START CONDITION. ON JANUARY 18, 2007 LAVATORY SMOKE DETECTOR ACTIVATED ON FINAL APPROACH. FLIGHT ATTENDANT DETECTED ODOR ON GROUND. MAINTENANCE REPLACED DETECTOR (P/N 46-0083-4) AND SYSTEM CHECKED SERVICEABLE. ON NEXT FLIGHT, DETECTOR ACTIVATED AGAIN WITH NO SMOKE OR ODOR. LOW BATTERY (TC N