What was found
DURING LEVEL CRUISE AT FL 330, CREW OBSERVED A LEVEL 2 ALERT (ENGINE 2 RPM LO) CONSIDERED SEVERE DAMAGE DUE TO NR 1 AND NR 2 RPM SPLIT WITH VERY ERRATIC NR 2 RPM. CREW ACCOMPLISHED SEVERE DAMAGE CHECKLIST IN QRH. PRESHUTDOWN PARAMETERS: NR 1 (94 PERCENT), EGT NORMAL, NR2 (32 PERCENT) PLUS OR MINUS 10 PERCENT AND ERRATIC, FF NORMAL, POST SHUTDOWN PARAMETERS: N1 (0), EGT LOW TEMP, NR 2 (8 PERCENT), FF 0 OIL PRESSURE 6-8 PSI APX. INSPECTED INLET AND EXHAUST; NO DISCREPANCIES FOUND. AFTER C/W MD1010 MM. RAN NR 2 ENG AND DUPLICATED MALFUNCTION. REMOVED AND REPLACED CORE SPEED SENSOR IAW MM. RAN NR 2 ENGINE OPS CHECKED NORMAL.