Date registered: Dec 2005
Vehicle: W211 E320 Bluetec R129 SL500 - $1300 car ........ Ford F350 6.7l
Location: Vegas MAN, Vegas
Mentioned: 10 Post(s)
Quoted: 1250 Post(s)
Spring is most likely part of chain tensioner, so logically the other parts are coming from there too.
I am not familiar with chain tensioner on 320, but on our diesels it can be unscrewed and removed on the side on the engine. All it takes is big wrench.
If you are lucky -putting new tensioner will solve the problem, if not -you might need engine rebuild. Keep your fingers crossed.