If this engine has not had a valve adjustment and has been neglected by the prior owner/s, you may have to do a couple more.
Do the first adjustment, put a 100 miles on it. do another etc...
If it has not been done in a long while. carbon builds up in the seats, and as the valves rotate, the carbon wears off and throws out the adj.

They are suppose to be done once a yr or every 15K miles.

Here is the list of DIY, it`s in the OM617 section.
PeachPartsWiki: Do It Yourself Articles - Mercedes Vehicles

Here is a good thread if you really want to get into replacing the chain and other related parts.

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works