W204 C220 CDI rough rattle when idling at 750rpm.

[Blue30]

Thanks I will keep it in mind, I would like to exchange the alternator with another one just to see if there is a difference.

I changed the pulley on my 2008 220CDi a year or two ago. It should freewheel in one direction and lock in the other. If it's locked up both ways the belt and tensioner will flap around like crazy on idle and you need a new one. You will need a special tool to change it, doesn't take long with the tool.

 

[Trickythemerc]

DemonTweeks were doing the Sealey pulley tool for about £19.00 when I bought mine.

 

[a111r]

These pulley pullers were 5 quid off ebay, which is fine for a tool you'll likely never use again.

 

[Trickythemerc]

A puller will be of zero use when changing a clutch pulley.

 

[Blue30]

Yeah it's not a puller you need it slides into the alternator shaft so you can hold it while you undo the pulley.

 

[RRV8]

Alternator pulley clutch ?

You are spot on, it was the alternator pulley. The engine sounds perfect since I replaced the pulley. Thanks for your onput

 

[RRV8]

You are spot on Trickythemerc. My clutch on my alternator is seized. I never new the even existed. I need to replace in and got to get the special tool for the job. Thanks everybody for your input. I will let ye know when I have a new one fitted.

I replaced the seized clutch pulley with a new one. What a difference!! It starts quieter, idles quite and switches off quieter. Thanks very much for your help.