What was found
ON FLIGHT 4788 - CREW REPORTED ON A FOUL ODOR COMING BLEED SYSTEM ESPECIALLY ON CLIMB AND DESCENT. ODOR RESIDUE WAS STILL PRESENT IN COCKPIT ON THE GROUND. AIRCRAFT REMOVED FROM SERVICE. REMOVED AND REPLACED ENGINE 1 ZERO CARBON SEAL. IT WAS DETERMINED THAT THE ENGINE HAD LOW OIL PRESSURE. UPON INVESTIGATION, IT WAS FOUND THAT THE NR 0 BEARING HAD SHIFTED LINEARLY IN THE FAN BEARING HOUSING. THE FAN BEARING HOUSING WAS REWORKED IN ACCORDANCE WITH SERVICE BULLETIN 72-331. LEAKS AND NO ODOR NOTED, AIRCRAFT RETURNED TO SERVICE.