You need to torque the head set captive bolt. Your headset is loose and is hammering the bearings and may have ruined them already.
To torque the headset captive bolt the handle bar to stem grip bolts need to be loosened, torque the headset captive bolt and then torque the stem bolts. If the stem was cut to long such that it is not approximately 0.5mm BELOW the edge of the top spacer, proper headset torque is not possible, trim the head tube.
LC