CDI 220 chattering noise at startup

[GlenH]

Hi,

I don’t know if anybody can shed any light on this one – the engine (CDI 220 C Class 202) makes a “chattering sound” is the only way I an describe it at start-up – this lasts for about 10 seconds then stops – if you watch the belt tensioner pulley on the front of the engine during this time it vibrates slightly – after about 10 seconds the slight vibration stops and the noise disappears – easily resolved then I thought? – nope – I replaced the tensioner pulley and it does exactly the same thing and the same noise – I’m 99% certain that the noise is coming from the tensioner pully area – has anybody had this before? – the noise only tends to occur if the car has been stood for a while ie. overnight – when it’s warm it starts without the noise.

Any help is much appreciated

GlenH

 

[abbos]

Hi Glen,

I had exactly this same problem less than 2 weeks ago. Mine was the manifold gasket. Although replaced and sounding much better, when it is very cold (morning start) you can still hear it slightly.

Might be worth looking into?

Good luck

 

[GlenH]

Cheers for the reply – that’s something I never thought of – I’ll certainly have a look and post a reply with the results.

Cheers again

 

[tzar]

cdi220 niose

hi glen,
spray some wd40 on the drive belt,

 

[Dieselman]

Remove the belt and start the car. If the noise persists it isn't hte tensioner or belt.

More likely it is the timing being advanced to compensate for the ignition lag. This usually causes the engien to be noisier and may well show up as resonance through components.
This will produce more power at the loss of refinement.

 

[tamrsoft]

If it's the 220 CDi engine, its more than likely the alternator pulley. These engines have a freewheel clutch within the alternator pulley to overcome this exact problem of poly-v-belt vibration, unfortunately the freewheel clutch mechanism has a habit of seizing up. The symptoms are severe belt vibration at idle especially when cold. Its a common problem and MB have issued a service note on it. Its easy to check, just remove the drive belt and check by hand that the pulley freewheels in one direction (CCW) but turns the alternator shaft in the CW direction. You can also check that this type of pulley is fitted to your alternator by prising off the plastic cap at the front of the pulley and you should see a splined recess designed to take a pulley removal tool.

 

[GlenH]

tamrsoft - many thanks for the info with regards the alternator clutch - you mentioned the splined tool to remove the pulley - do you know if this is something that you can only get from a MB dealer?

Cheers again

GlenH

 

[GlenH]

A bit of advice if anybody can help with regards this infamous alternator seizing clutch problem that appears to be quite common on cdi engines, to get the pulley off the alternator you need a splined socket – the link;

http://www.cranbrooktools.co.uk/cgi-bin/WebObjects/MPMall.woa/wa/viewPage?cat=921&site=39

shows two different types about halfway down the page for bosch alternators (Ref: L3307 and Ref: L3404) – does anybody have any ideas which one it would (or could) be? – an educated guess would be the T50 version as the engine has various torx bolts fitted that I can see – but I’ve learned the hard way never to assume anything!.

Cheers for any advice

GlenH

 

[tamrsoft]

Glenh

The details are as follows:

Pulley (freewheel) – P/N 611 155 0415

Pulley socket tool – P/N 602 589 00 10 00 (serrated wrench 17 x 20 mm DIN 5481 / waf 17 mm)

You can buy the socket tool from from MB Dealer (it's about £27) or you can get them to do the job which I believe is about £120. Apparently the job can be done with the alternator in situ, a hex key can be inserted in the end of the shaft to hold it stationary while the pulley is removed using the socket. Mine has seized also and I am about to replace it, but it looks as though the hex slot in the end of my shaft has been butchered (previous MB workshop ???) so I have no way of holding the shaft stationary. I may just remove the alternator and disassemble so that I can hold the stator by hand while removing the pulley.

 

[GlenH]

Tamrsoft,

Thanks for the info so far it’s been a great help - does the pulley need completely replacing or can the clutch be easily unseized do you know?

 

[tamrsoft]

As far as I am aware, the pulley is a machine sealed unit and if disassembled probably cannot be re-assembled. I will certainly try to disassemble mine but I expect to have to replace completely.

 

[liverpool 21]

tool required is M10 spline type ,not the torx type even though torx is used all over 220 cdi engine, costs £22:50 (inc post) from UKtools , and you will have to grind the splined socket retaining ring off M10 shaft to allow socket to fully engage into pulley..or if you are anyware near liverpool you can borrow mine

 

[tamrsoft]

Did you replace with alternator in situ and if so, what tool did you use to hold the shaft stationary ? Apparently the Stealers insist on removing the alternator and consequently charging for the extra time to do so.

 

[GlenH]

Liverpool 21 is spot on (and cheers for the tool offer but I live in Manchester though) – I took the plastic cap off the alternator last night and used a small inspection mirror (cheers Maplin £2.99!) to check what type of shaft it is and it is the M10 rather than the Torx – I rang the dealer this morning and it’s £23 for a new pulley – it would be interesting to know how easy it is to do this whilst the alternator is still fitted.
I’ve also found the tool (laser make them) on the cranbrook tools website (link is in one of my posts higher up on this page) for £18.50 delivered.

Cheers for everybody’s help so far

GlenH

 

[tamrsoft]

Glenh

Did you have the P/N for the splined socket drive from Cranbrook tools, and did they confirm whether or not it was compatible for this particluar pulley fitting. I have looked at their web site but did not see it advertised.
I also have a mismatch on the pulley price quoted by your Dealer and my local MB Dealer, they have priced it at £74 + VAT, do you have a special price deal with them ?

 

[GlenH]

The tool reference on the cranbrook website is L3307 but I haven’t confirmed whether it’s the correct one or not – looking at the pictures it does look like it will do the job though – and no I haven’t got a special deal with the dealer I’m just Joe public – he did quote a different part number than the one you have given though - he gave me A014 997 0492 – price £23.35 I gave him the chassis number etc of my car which is a C class 202 CDI 220.

Cheers

GlenH

 

[tamrsoft]

Hmmmm - strange, different car but same engine. I think I will remove the old pulley first before buying the new just in case the original P/N given to me was incorrect and yours is the right one, £50 is quite a difference. Good luck with the job, I would be interested in your feedback when you get the job done.