98 diesel chugging & clutch problem

My 98 diesel 3 door polo chuggs when driven at about 2000revs. it only chuggs when it is constantly driven at 2000revs and is ok above and below that rpm. has anyone had this problem and what might be causing it??

Also clutch is making a rattling noise when the clucth is pressed in. if i just sit in the car while running and press the clutch i can hear a rattle like a clutch bearing is gone. again has anyone got any advice and if so how do i fix the problem. Thanks