MONDEO TDCI,LOUD TAPPETY NOISE,GUTTLES,SMOKING?

MONDEO 2002,TDCI,130,..STARTS VERY WELL,ON TICKOVER IS VERY NOISY(TAPPETY NOISE),NO SMOKE..WHEN YOU REV UP,NOISE GETS QUITER,STILL NO EXCESSIVE SMOKE,BUT A SMALL MISFIRE AROUND 4000-5000 REVS...ON THE ROAD ,UNDER LOAD,IT IS VERY SLOW,AND SMOKES BADLY(BLUE/GREYISH)..ANY IDEAS????WELLL APPRECIATED