My 3 yrs old diesel isuzu ambassador was producing abnormal sound from engine side..replaced piston cylinder,all related parts,Valve n valve head etc..but this sound is observed even after replacing all these items..service people are saying that it is related to pump and nozzle..but i cleaned the nozzles also and they told me that its not time yet to replace them as they are all in good condition..still that sound is persisting..I invested a lot for this..but no result..now i found that the sound is coming while applying clutch..and engine seems to be more rough in the first two gears..i\'ve changed the clutch set completely..is it due to the wrong setting of clutch?kindly help me by giving a reply..