As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENGINE OIL FILTER DIFFERENTIAL WARNING EICAS ILLUMINATED. REPLACED ENGINE. SUBSEQUENT SHOP TEARDOWN REVEALED FAILURE OF THE NR 1 BEARING. BOTH OF THE BEARING'S INNER RACEWAY HALVES HAD MACHINED THE CAGE INNER DIAMETER 360 DEGREES.