As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - ON CLIMB-OUT, THE NR 2 ENGINE OIL FILTER BYPASS LIGHT CAME ON, FOLLOWED BY A LOSS OF OIL QUANTITY AND A RISE IN OIL TEMPERATURE. ENGINE SHUTDOWN, FUEL DUMP AND ACFT RETURNED TO ORD. POST FLIGHT INSPECTION OF ENGINE SHOWED NO EXTERNAL LEAKS. ENGINE MAIN OIL FILTER WAS FOUND FULL OF THICK BLACK OIL. SUSPECT NR 4 BEARING CARBON SEAL FAILURE. ACFT WAS FERRIED TO MAINTENANCE BASE FOR ENGINE CHANGE.