What was found
(CAN) FROM A PILOT REPORT RECTIFICATION, A GROUND RUN OF THE NR 1 ENGINE WAS REQUIRED FOLLOWING A COMPONENT CHANGE. DURING THE START CYCLE OF THE GROUND RUN. THE LAME CONDUCTING THE GROUND RUN IDENTIFIED AN ENGINE VIBRATION THROUGH THE FLIGHT DECK CONTROL CONDITION LEVER. NO FLIGHT CREW HAD WRITTEN UP AN ENGINE VIBRATION DEFECT PRIOR TO THIS GROUND RUN. FURTHERMORE WITH THE ENGINE AT IDLE SPEED THE VIBRATION COULD BE INCREASED/DECREASED WITH SOME MANIPULATION OF THE CONDITION LEVER. FOLLOWING EXTENSIVE COLLABORATION WITH THE ENGINE MANUFACTURER AND FOLLOWING SUGGESTED TROUBLESHOOTING, ON ADVISE FROM THE MANUFACTURER THE ENGINE WAS REMOVED.