FIXED

When we fitted first belt kit we replaced stud for tensioner when it came back the stud had snapped off flush with head. we got specialist out to drill out stud and fit a heli coil.weve fitted a new belt kit and reassembled it and engine runs fine. just worried how it happened in the first place.may be cam lobes worn causeing vibration? car has done 145000 miles.dont want it comming back again.can i put in writing that possible engine wear i cannot guarantee this? Regards Paul