What was found
FIVE MINUTES INTO CRUISE NR 3 ENGINE SHOWED N1 EXCEEDANCE UP TO 209.3 PERCENT BROUGHT NR 3 THROTTLE TO IDLE. INDICATIONS CAME BACK TO NORMAL, FIVE MINUTES LATER NR 3 N1 JUMPED AROUND THEN BACK TO NORMAL FOR REST OF FLIGHT. TROUBLESHOT IAW FIM MANUAL 77-11-01 PAGE 2, R & R FAN SPEED SENSOR IAW MM 77-11-01-2-0. RAN ENGINE IAW JRH , WITH SATISFACTORY OPS . INTERROGATED VIAS THRU CFDS, NR 3 ENGINE EXCEEDANCE ERASED. ACFT OK FOR SERVICE.