ML 270 CDI auto, idler pulley broke

[Garista]

Hello.

So I installed a new water cooled alternator, all went fine, took ages to get the part though and the job was not exactly easy peasy. Worked great no problems.
Then the other day on a trip the idler pulley (which is plastic) completely broke, and left the belt running on the central hub bit, which smoked!!
So I am going to have to change it. Probably I should have serviced this part and the belt at the same time as the new alternator. Now I know they do a kit that includes the idler, the belt and the tensioner pulley. You live and learn.
If you have any tips let me know, otherwise maybe this will help someone.

 

[Blobcat]

Idler is a non serviceable item - better off just replacing it - mine did similar - I'd recommend changing the tensioner at the same time as that will probably be on the way out as well..

(I did the idler on mine as the bearing gave out - the tensioner went a week or so later...)

Give Mercedes Grangemouth a call - they give forum discount

Thread I did when I changed mine on my M272 engine

M272 Serpentine Belt Idler and Tensioner failure and replacement

Sat waiting for garage door to open tonight and thought “that’s a strange noise the door is making”. Then realised I could smell plastic burning... :( Engine off, bonnet open, front engine cover off and bits of belt strewn around :( Top idler wheel completely gone... You can see bits of...

forums.mercedesclub.org.uk

 

[rifiki]

You are lucky, had similar problem. The tension pulley seized and the shredded belt wrapped it's self the crank shaft between pulley and engine block causing more problems.

 

[Garista]

You are lucky, had similar problem. The tension pulley seized and the shredded belt wrapped it's self the crank shaft between pulley and engine block causing more problems.

Ouch! Yes we were lucky, but quite used to being very sensitive to the noises and smells after doing any work.
I think I should really buy the whole kit, but I will do the idler pulley first and get the other parts separately, as I want to make sure it is febi bilstein one.

 

[Garista]

Idler is a non serviceable item - better off just replacing it - mine did similar - I'd recommend changing the tensioner at the same time as that will probably be on the way out as well..

(I did the idler on mine as the bearing gave out - the tensioner went a week or so later...)

Give Mercedes Grangemouth a call - they give forum discount

Thread I did when I changed mine on my M272 engine

M272 Serpentine Belt Idler and Tensioner failure and replacement

Sat waiting for garage door to open tonight and thought “that’s a strange noise the door is making”. Then realised I could smell plastic burning... :( Engine off, bonnet open, front engine cover off and bits of belt strewn around :( Top idler wheel completely gone... You can see bits of...

forums.mercedesclub.org.uk

Is the tensioner pulley also plastic?
Sounds like a good idea to do it all at the same time. So I won't of course.

 

[Blobcat]

Is the tensioner pulley also plastic?
Sounds like a good idea to do it all at the same time. So I won't of course.

It is, please take a look at the thread I posted

 

[rifiki]

Change the lot and only use branded ones, SKF, Febi etc.

 

[Garista]

It is, please take a look at the thread I posted

Yes, will, thanks.

 

[Garista]

Change the lot and only use branded ones, SKF, Febi etc.

I put on a febi-Bilstein idler. Searching for the other two at the moment. On a budget but will get quality.

 

[Garista]

Was quite easy to put on, not much access but it is high up, I found I could loosen the fittings for the radiator and pull it back a bit out the way. You need a short torx bit in a ratcheting spanner ideally.

The belt looks quite good but I will change it soon, and the tensioner. Saving up .