What was found
NR 2 ENGINE N1, FUEL FLOW, AND EGT BEGAN TO OSCILLATE AT NEAR TOP OF CLIMB AFTER CENTER TANK FUEL USED. N1 OSCILLATED +/- 10 PERCENT. RAN QRH FOR ENGINE STALL - SURGE. REDUCED THRUST, ENGINE CONTINUED TO OSCILLATE. AUTOTHROTTLE OFF. AFTER SEVERAL MINUTES, OSCILLATION CEASED AND ENGINE OPERATED NORMALLY. ENGINE DID NOT APPEAR TO EXCEED LIMITS. ACFT GROUNDED. TROUBLESHOOTING IAW AMM 71-00-00-280-F00. R & R FOQA DATA IAW AMM 31-31-22-470-807. PERFORMED EEC BITE IAW FIM 73-00-T/C 801. SHOWED FAULT MESSAGE 73-20332. NO ENGINE EXCEEDANCES DETECTED. PERFORMED T/C NG-73EO-11740 IAW FIM TASK 73-25, TASK 802. ALL TESTS PASSED. ORIGINAL FAULT FOUND TO BE AN INTERMITTENT AND SELF CLEARING FAULT IAW T/C NG-73EO-11740, STEP 28.