As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE CLIMBING THROUGH FL 330 E1 ITT WAS NOTED TO BE FLUCTUATING BETWEEN 600 - 800. N2 WAS FLUCTUATING +- 5%. N1 DROPPED BELOW 45% NO ENG LIMITATIONS WERE SEEN IN EXCEDENCE. ACFT WAS REMOVED FROM SERVICE. COMPLIED WITH ALL TROUBLE SHOOTING PROCEDURES FOUND NO DEFECTS. REPLACED ENG DUE TO COKING ON CTR SUMP IAW NRWC 850-DFW-01363 & 850-DFW-01376 FCF REQUIRED.