What was found
AFTER TAKEOFF, THE CREW ON N604AL HEARD A LOUD NOISE IN THE NOSE GEAR. CREW ELECTED TO RETURN TO SJO. ACFT LANDED WITHOUT INCIDENT. AFTER INSPECTION, NO PROBLEM COULD BE FOUND. CREW ATTEMPED TO TAKEOFF AGAIN, BUT PERFORMED AN AIR TURNBACK WITH SAME PROBLEM. MAINTENANCE FOUND NO PROBLEM AFTER AN EXTENSIVE INSPECTION. A FEW ADJUSTMENTS WERE MADE AND THE CREW DEPARTED AGAIN. PROBLEM DID NOT RE-OCCUR, THE FLIGHT CONTINUED ON TO ELP.