As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EN ROUTE BUR-PDX, WITH DIVERSION TO SMF, IN FLIGHT SHUTDOWN AND DIVERSION DUE TO INDICATION OF PRECIPITOUS DECREASE IN OIL QUANTITY (FROM 13.5 TO 10 QUARTS) DURING THE FIRST 30 MINUTES OF FLIGHT. ENGINE REPLACED. SHOP TEARDOWN INVESTIGATION REVEALED DISENTIGRATED NR 4 BEARING CARBON SEAL AS CAUSE OF OIL LOSS. ENGINE CURRENTLY UNDER REPAIR.