What was found
LOUD METALLIC VIBRATION SOUND HEARD AT L2 DOOR. CAN BE FELT WHEN HAND IS PLACED ON DOOR. DUE TO HISTORY OF NOISE AND VIBRATION AND CREW REPORT OF NOISE INTERFERRING WITH CREW COMMUNICATION MUST CHECK DOOR COVER PLATE, SEALS , FRAME AREA, AND PRESSURIZE TO ISOLATE AND CORRECT AS REQUIRED PRIOR TO FURTHER FLIGHT. CHECKED DOOR COVER PLATE, SEALS AND DOOR FRAMES NO DEFECT FOUND. PRESSURIZED ACFT UP TO 8, 4PSI IAW MM, NO LEAKS NOTED.