Knock at idle, anyone else have this?

[bigmistake]

Recently purchased S40 2008 d5 auto r-design, 114k miles, starts fine from cold but as a horrible 'knocking' from the engine when put into d or r (when load put onto engine), hear it more inside the car than outside.
This noise is more pronounced when engine is cold but can still be heard when up to temperature.
It sounds like it is coming from one cylinder, too heavy to be piston slap, originally thought it was a diesel combustion type knock.
The car as had 5 matched injectors fitted from a 4k d5 and this as improved the smoothness however can detect a misfire if the revs are held 1000 rpm ish and above on light throttle if in neutral also at certain times when driving so something is not right.
Wondered if any other S40 d5 owners had experienced this noise, if it is normal for this car.
Have read a lot about egr systems getting clogged causing a problem, maybe my next thing to look at
Welcome any thoughts

[Juhani65]

Hi! I have similar knock-sound in D5 engine (185hp -08, 225tkm), i think. Not too good starting at cold, slowly this knock comes up (about 10s) at idle and disappears when engine is hot. It has come more bad after half year and i can hear it now also when engine is hot. It is not coming from fuel injectors. Those are just tested and they are as good as new ones. Also auxiliary belt devices are good, checked with no belt-and sound is still there.
I was just running car outside and notice (with stetoscope) that same kind sound is coming from plastic swirl throttle mechanism (from flap axel inside intake manifold) ... if You solve this, please told how.

[bigmistake]

Hi Juhani65, still not cured knocking although car settled down with the low mileage injectors to run smooth and plenty of power. The knocking is louder from inside the car than outside, when cold sounds like big end knock from one cylinder almost.
When engine is fully hot can barely hear the knocking.
Surely there must be other D5 owners who have experienced this ?