As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT #4 ENG. OIL QUANITY DROPPED TO ZERO. OVER THE NEXT 20 MINUTES THE OIL PRESSURE DROPPED STEADILY REACHIMG 10 PSI(RED ZONE) THEN IT FLUCTUATED BETWEEN 10-13 BEFORE STEADY RED WE SHU #4 ENGINE CHANGED.C/W MASTER CHIP DETECTOR INSPECTION REFERENCE: TASK 79-21-05-202-024-J00 AT REQUEST OF POWER PLANT ENGINEERING , NO DEFECTS NOTED.