engine knock

[steven.0424]

engine making racket put injectors off olld head in quietened it down slightly put others back in made hell of racket when first started then quieten down but not as quiet as the others so put them back would pull apart to clean but dont have pop tester runing ve pump sd25 motor does it sound like injector problem im new to diesel engines have manual reading all the time

[steven.0424]

only seems to knock at idle when revved over 2000rpm seems to stop and not as noticable wnen engine warmed up any help would be great as i dont want to self destruct the engine