grey smoke and chatting from inlet at high revs

[richblue transit]

hi ive got a 98 transit 2.5diesel with the bosch pump my van is grey smoking and chatting through inlet manifold at high rev and really down on power just had brand new injectors and lift pump and seoand hand injection pump egr valve is blanked offn any ideas thanks

[jay]

broken valve spring or chipped valve..is a possible..can u hear it popping in the inlet manifold while at idle.

[richblue transit]

hi it were only poping at high revs seems to be abit lumpey at idle and it loss loads of power ive took the head off today i cant see anything gonna get it checked over