What was found
IAH - FLIGHT 2367, THE CREW REPORTED SMOKE IN THE CABIN AND A LAV SMOKE WARNING AFTER T/O. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE AIRCRAFT, PERFORMED GROUND RUNS AND FOUND THE ODOR TO BE RESIDUAL OIL. THE AIRCRAFT WAS TEST FLOWN SATISFACTORILY, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.