As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
KCMH TO CMI: ON TAKEOFF ROLL THE MASTER WARNING ILLUMINATED "LEFT ENGINE OIL" ALONG WITH THE AURAL WARNING "ENGINE OIL" ACTIVATED. THE TAKEOFF WAS ABORTED AND AFTER THE LEFT ENGINE WAS SHUT DOWN, OIL WAS SEEN LEAKING FROM THE LEFT ENGINE. MAINTENANCE FOUND ONE END OF THE OIL COOLER BYPASS LINE LOOSE. THE FITTING WAS TORQUED AND AREA CLEANED OF OIL. ENGINE WAS GROUND RUN AND CHECKED FOR LEAKS WITH NONE FOUND. ENGINE OIL QUANTITY SERVICED AND AIRCRAFT WAS RETURNED TO SERVICE.