Poly-V Belt on M111 aspro 98 C230 - DIY?
 

My poly-v belt is starting to show some signs of wear, and since we're heading on a 10,000 km trip through Alaska this summer, I want to take care of anything that could leave us stranded in the middle of nowhere.

The belt tensioner is a bit of a frieign device to me, in how it works. I'm used to the "slotted" alternator housing, you know...

Should I just bite the wallet and have the dealer do the job, or can I tackle this at home?

Hhhhmmm...

Not exactly sure about your model but take a look at the front of the tensioner pulley. There should be a nut there. Get the appropriate size socket wrench, put it on that nut and try turning it. You will have to study the way the belt is around it but you should be able to figure out which way it goes to relieve tension on the belt. Once you figure that out turn it as far as it will travel and then you should be able to slip the belt off of one of the pulleys to enable you to replace it. Not sure if you have to remove the fan shroud on this model or not. Make sure you have a drawing or sketch of the proper routing prior to removing the belt.

That's simple! The nut is some sort of torx that I'll have to hunt for, but shouldn't be too bad.

I don't need to remove the fan shroud, as I can nearly get myself between the engine and the rad, there's so much room. One of the benefits of these four banger cars.

The manual has a belt routing diagram, but I'll probably take some pics just to make sure.

John,
When you get the proper socket try turning it easily with the socket and see if the tensioner pulley starts moving to allow loosening the belt. If it does then keep turning it till it won't move anymore. That is how the ones I am familiar with work. The tensioner pulley bracket is spring loaded. If the pulley does not start moving then yours is different and you will have to get an answer from someone that is more familiar with this model. Should be pretty straight forward on which direction it should turn based on the way the belt wraps around it.