As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW EXECUTED AN AIR RETURN, FOLLOWING THE NR 1 ENGINE "OIL STRAINER CLOG" WARNING LIGHT ILLUMINATING. SEQUENCE OF EVENTS INCLUDE THE CLOG MESSAGE AT 1000 FT, COMPLYING WITH THE QRH AND THE MESSAGE REMAINING AT IDLE, SO THE CREW THEN INITIATED THE RETURN AND DECLARED AN EMERGENCY. MAINTENANCE FOUND METAL ON CHIP DETECTOR AND IN OIL FILTER. LAB RESULTS SHOW METAL COMING FROM THE MAIN BEARING AREAS. ENGINE HAS BEEN REPLACED.