@dazza your becoming a real guru on this subject now fella!
All I'll say on this subject is, I had dieseling sound from engine, so much so I could hear it inside the car with the doors shut.
So changed the cam tensioner, chain and cam adjuster. Now all is lovely and quiet, no embarrassing diesel noise for me.
I would say, if you can hear the diesel sound from inside your car, get the parts changed. If you cant leave alone.
Dazza helped me a lot with advice on mine, listen to what he has to say