peugeot 2.1 diesel 12 valve top end knock/rattle?

hi, r redg peugeot 406 2.1 12 valve,when you start engine loud knocking/rattle at top end of engine,and smokes realy bad,not to bad on tickover but when you increase the refs the knock/rattle gets louder and smokes a lot more,have checked the injectors,cambelt timing,took rocker cover off and all looks as it should started engine and all rockers etc seems to be working,engine only done 130.000 miles any hints thanks