New to the Forum and hope i can get some help here?
Have Bought and driven a Focus 1.8 TD estate 2001 (Endura D1 Engine)for about 3 wks now no problem till yesterday?
Started the car bit of a misfire but cleared,but then once you reach 3000rpm,sounds like all hell has let loose,a bag of nails.
Dosen't change note or performance alters just very noisy.
Scared to drive it now,seems fine on idle except for the ocassional misfire.
can anyone suggest where to look?

with out hearing the car,, my best guest is to have a look at the timing belt, it is possible it may have slipped. just one tooth out will make it sound rough, to check the timing you need a pining kit.

check your exhaust manifold and ensure that the brackets havent rusted through, saw this only the other day... it does make it sound much more noisy...