As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOS - FLT 4252 - CREW NOTICED ENGINE TEMPS HIGHER THAN RIGHT, BUT NOT OUT OF LIMITS. CREW REDUCED POWER TO MATCH TEMPS AND LEFT ENGINE DID NOT MAKE CHARTED TORQUE. AIRCRAFT RETURNED TO BOS WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED THE T4.5 TRIMMER IAW GE MM. AIRCRAFT RETURNED TO SERVICE. (X)