What was found
INSTALLED REPAIRED SERVICEABLE ENG ON THE NR 2 POSITION ON ACFT. DURING THE ENG LEAK & RUN UP CHECKS WE DISCOVERED THAT THE T1 PROBE HOUSING THAT IS IN THE INLET AIR STREAM HAS BROKEN OFF & DAMAGED THE FAN, FAN LINER & BYPASS DUCT. REMOVED ENG & RETURNED FOR REPAIR. THE T1 PROBE HOUSING WAS NOT DISTURBED AT THE ENG CHANGE. WE BELIEVE THE T1 PROBE HOUSING HAD BEEN DAMAGED DURING A PREVIOUS INSTALLATION & CRACKED THE AIR INLET PROBE. THE VIBRATIONS FROM THE POWER RUN CAUSED THE PROBE TO BREAK OFF & DAMAGE THE ENG.