What was found
(CAN) ON TAKE-OFF ROLL, LOW OIL PRESSURE CAUTION LIGHT FLICKERED.TAKE-OFF ABORTED.SECOND ATTEMPT WAS MADE OBSERVING PRESSURE GAUGE AND OIL PRESSURE CAUTION LIGHT FLICKERED AGAIN AND OIL PRESSURE PHYSICALLY CONFIRMED TO BE LOW BY GAUGE. TAKE OFF ABORTED AGAIN AND AIRCRAFT RETURNED TO GATE. UPON INVESTIGATION, MAINTENANCE FOUND OIL QAUNTITY LOW, AND NR 3,4,5 BEARING SCAVENGE TUBES LEAKING. O-RINGS WERE REPLACED AND ENGINE GROUND RUN. TEST FLIGHT WAS ALSO CARRIED OUT AND NO LEAKS WERE OBSERVED. L/H ENGINE WAS STARTED AT -25 DUE TO FAILURE OF ENGINE PRE-HEAT SYSTEM, SUSPECT PROBLEM OCCURED DUE TO COLD TEMPERATURE START.