I am only speculating because I do not know for sure. There is a big washer behind the belt tensioner. It may be missing, hence the tensoner is bolted towards the engine by about 1/8". The idle pulley is bolted to the tensioner so it is also off by 1/8". It should not really matter as the belt is still wrap round the idle pulley over 90%. May be you can shim up the idle pulley ??

You can remove belt tensioner and take a look. It can be removed without removing the water pump pulley on the OM603.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

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