fiesta 1.6 tdci thud when turning engine off

[w.collins]

hi  got  a  niggling problem on my 2005  zetec s tdci  when starting  and turning off   engine  shudders  then  a clunk  at  the  front on the   right  almost like when a  exhaust rattles   ive checked all under  and cant find anything that would make  a contact.

its not flywheel  or clutch related   as its wrong side and  exhaust is not near  anywhere to make contact   its  got me stumped and  annoyed   as  other  than this its great  starts up on the button idles well  and  great performance  and  ive changed  gearbox dog leg and upper mount on drivers side