What was found
CREW HEARD A LOUD BANG AT START OF TAKEOFF ROLL, ALL ENGINE PARAMETERS WERE FINE GOT EITHER AN E2 OUT OR E2 FAIL. CREW WAS UNSURE RETURNED TO GATE IN JFK. REPLACED ENGINE NR 2. ENGINE NR 2 P/N OFF/ON AE3007A1/3, ENGINE NR 2 S/N OFF CAE311947, S/N ON CAE311770. (M)