FrankI

I have a 2004 C230 Kompressor 1.8L (M271). My car is the one before they went to the staggered wheels. I would like a clear understanding of how to change the belt. The Haynes manual says some models have a cast-in-hex on the tensioner arm that will accept a wrench or socket. On other models, place a Torx-bit onto the fastener in the center of the pulley.

It's really difficult to see what I have. Any advise please, exact tools required?

Boom vang

I just did mine yesterday, as a sidebar be careful where you put your hand to lean in to the car as I broke the plastic pressure line to the overflow (right side of the engine) and had to McGuiver a stopgap solution with a golf tee in order to drive my car home. This frail plastic part is vulnerable and gets weaker because of the heat from the exhaust manifold.

you have to remove the Wideband silencer first (A VERY FIDDLY JOB)

2 Bolts (E12 or E10 sockets) to undo the silencer from the front of the engine
2 hose clamps (8mm) one to a small pipe that goes to a valve and the other is a large one going to the SC
1 spring hose pressure connect ( a little fiddly to undo) going to the intercooler

Once you have undone the WB silencer, just drop it to the bottom so it is out of the way (no need to take it out)

Now you can take the belt off

To release the pressure of the tensioner you need a Torx 55 socket (some say it is a Torx 60; I found it impossible to find one and the 55 worked fine) to insert to below the tensioner and rotate in CCW to take off the slack. Make sure you have a firm grip as the spring is strong and you can jam (or break a finger) between the ratchet handle and the main pulley of the engine.

To install, make sure the belt is on the tensioner first and then when you rotate CCW the tensioner, slip the remaining slack on the the large idler pulley

I found that the real problem were my extensions 6" and 3", neither are the right size and if I get a small extension such as a 1-1.5" it would make my job a lot easier

FrankI

Is there a way without removing the WB silencer????

Boom vang

Nope as the silencer blocks the insertion place to release the tension of the belt

the WB silencer is not hard to remove it is just awkward as there is not a lot of room to work around and without that 1.5" extension I could not get the full radius of my ratchet drive.

Seems that they want people with small hands with long arms able to do gymnastics in order to get to some of the parts to remove

FrankI

Thanks for your advise!! How do you remove the spring hose pressure connect? Do you need a special tool?

Boom vang

I just used a small flat screwdriver and lifted the tabs- worked fine