As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EN ROUTE DTW - DLH, NR 4 ENGINE OIL PRESSURE LIGHT ILLUMINATED, INDICATION WAS AT ZERO. CREW STARTED TO PERFORM QRH PROCEDURES WHEN ENGINE NR 4 OVERSPEED AND SHUT ITSELF DOWN. COMPLETED QRH AND DIVERTED TO TVC. MAINTENANCE REPLACED NR 4 ENGINE ASSEMBLY IAW AMM AND ASSOCIATED ENGINE CHANGE TASK CARDS. OPS AND LEAK CHECK GOOD.