What was found
DURING INITIAL TAKEOFF ROLL, ALL OIL QUANTITY INDICATIONS WERE NORMAL AT 1.4 EPR. AS THROTTLES WERE ADVANCED TO FLEX TAKEOFF POWER, THE OIL QUANTITY ON ENGINE NR 3 DECREASED TO 1/2 GALLON INDICATION. ABORTED TAKEOFF AT 90 KNOTS AND RETURNED TO GATE. REMOVED AND REPLACED NR 3 ENGINE OIL QUANTITY TRANSMITTER PER MM 79-31-01, OPS AND LEAK CHECK GOOD.