W203 Engine block/tensioner

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New Member
Sep 3, 2008
Any help appreciated.
C220 Cdi, W203.
V-poly belt comes off while driving. Seemingly no damage. Limp home.
Belt explains the squeeking/whining sound on staring/switch off. RAC determine the cause as a 'loose tensioner'. Off we go to mercedes Benz world and purchase new on. RAC attempt to fit but on tighteining one of the two new bolts - it shears off !!!!

It was going directly into the engine block, where now with the aid of a mirror I can see the end of a sheard off bolt sticking out.

Result: no tensioner, no belt, no driving!

Presumably I now face the cost of removing the radiator and AC units to access the bolt and start to drill it out/re-dye cut the hole. re-drill a home in the new tensioner, find a new bolt to fit the larger hole, mount the belt and jobs done.

Any help welcome, even if just to say go and enjoy the cost of MB's labour charges to do this or risk further damage.

How did the RAC man manage to snap it?
There is no tension against to sheared bolt so it may be possible to unscrew it with a sharp screwdriver. Alternatively a small drill hole down the centre and use an Ezi-out reverse thread remover.

Surely the RAC should get this done for you.
He snapped it using a wrench....he was doing his best though
Dieselman - thanks very much. Ezi-out is the route we're going to try on Thursday. The issue will be whether we can drill out without removing teh rad and ac units to get good access...

Here's hoping.
You MIGHT get to it with a right angled drill attachment, but try a short, sharp screwdriver first, it just might work.

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