What was found
DURING CRUISE FROM KTOL NR 4 ENGINE FIRE WARNING INTERMITTENTLY GOING OFF, THEN CAME ON STEADY. THE CREW SHUTDOWN NUMBER FOUR ENGINE, LIGHT IN HANDLE REMAINED ON UNTIL FL 18,000 ON DESCENT. THE CREW DISCHARGED BOTH FIRE BOTTLES. THE CREW LANDED IN KDEN WITHOUT FURTHER INCIDENT. MAINTENANCE INSPECTED AND FOUND LEFT FAN LOOP CONNECTOR CONTAMINATED WITH OIL. MAINTENANCE CLEANED CONNECTOR. REPLACED BOTH FIRE BOTTLES. OPERATIONAL CHECK GOOD IAW GMM 3.124 AND FCD 7/18/08. AIRCRAFT WAS RETURNED TO SERVICE.