As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB FROM KTOL TO KBNA THE NR 3 ENGINE EGT BEGAN TO FLUCUATE BOTH ANALOG AND DIGITAL +/- 50 DEGREES C. CREW RETURNED AIRCRAFT TO KTOL AND FLUCUATION CONTINUED THROUGH DESCENT AND LANDING. AIRCRAFT LANDED IN KTOL WITHOUT INCIDENT. AN INSPECTION IS ON GOING. AS MORE INFORMATION BECOMES AVAILABLE IT WILL BE PROVIDED.