What was found
AFTER TAKEOFF, STRANGE GRINDING SOUND FROM NOSE GEAR AREA FOLLOWED BY A NOSE DOOR MASTER WARNING. MESSAGE EVENTUALLY WENT AWAY AFTER ABOUT 15 SECONDS SOUND STOPPED SHORTLY AFTER. THE REST OF THE FLIGHT WAS UNEVENTFUL ALSO FIRST OFFICE DID NOT NOTICE ANYTHING ON POSTFLIGHT. INSPECTED NLG IAW AMM 33-21-01. FOUND NO DEFECTS. PERFORMED MULTIPLE NLG GEAR SWINGS IAW AMM 32-33-00. OPS CHECK GOOD. NO NOISES DETECTED. NO FAULT CODES FOUND IN PSEU. PERFORMED NLG LUBRICATION IAW AMM 12-20-32. OK FOR SERVICE.