First of all,we have to make a difference between Vanos noise(diesel sound) and chain rattle...
Vanos rattle has two main causes,the diaphragm springs,no3 an no5,as well as play in the helical gears no2.
The diaphragm springs were updated on the 2001 models and make the car way more silent.
When installing the Vanos units with the gears,you have to compensate for the play anyway...
Chain noise is usually a combination of chain stretch(no1),the chain guide no6 loosing parts or tensioner no20 going bad.
I spent the last 48hours with a car that had rattle.
Was hard to say if Vanos or chain...
First I tried compensating the play of the gears,did not help,also a new tensioner no20.
It ended up in changing all chain guides,all chains,diaphragm springs,new bolts for the sprocket(no5) as these were upgraded to stronger ones and rebuilding the Vanos units themselves as on one oil pump the pistons seized(thankfully I always have some Vanos units to dismantle for parts,otherwise the only option would have been 2500€ for a brand new unit:biggrinbounce
The rest of the parts my dealer had fortunately in stock(they know that I do this work at least once a month:haha
Overall an 40 hour job to do it proper.
With your noise,you will only find out what is going on when the engine is open.That is the truth.
What I have found so far on cars with similar noises:
-chain tensioner no 20 collapsed
-chain guide no6 broken
-Vanos oil pump seized
-chain sprocket bolts no 5 backed out and destroyed Vanos units
-main chain stretched
-diaphragm springs worn
-chain tensioner between cams(no8 in the first pic) briken
-chains between the cams stretched
If you really want the car silent,replace all the stuff mentioned on both diagrams and rebuild the Vanos units.
End of story.
Will set you back about 1300€ in parts and loads of work.
Ignore TIS regarding taking the cylinder heads away for removing the lower timing chain case.
That is utterly bullshite and not needed.
If you have further questions,let me know.