E300 W210 Vibration / Noise on tick over.......

[paulquinlan]

E300 (W210) Developed a vibration / noise on tick over, once over 750rpm it disapears. Thought at first it might be the exhaust, but that has checked out fne. Think i have tracked it down to the pulley that drives the fan belt - when you put a bit of WD40 on it it seems to disapear for a day or two. Anyone had a similar problem. Ease of repair? Cost??

 

[tamrsoft]

If it's the same as the 220 CDi engine, the alternator pulley has a freewheel clutch action inside it, it is common for this mechanism to seize and so not freewheel. This causes severe drive belt vibration on idle. I believe cost of pulley is about £90 plus about £23 pounds for the multi-splined removal tool if you DIY. You can check if its seized by removing drive belt and check that the pulley freewheels in an ACW direction and turns the alternator shaft in a CW direction.

 

[Parrot of Doom]

At the front of the engine, just between the head and the fan, there are two small devices that look like pistons. The one on the right is a spring - the one on the left is an oil-filled piston. They act together to dampen vibrations from the engine.

I've just today had mine replaced by a mate of mine. The spring was fine, it was the piston that was causing the noise. £30 for a new one, although its a bit tricky to fit as the bolt only just clears the eyelet to remove it, the fan is in the way The old one had very badly worn rubbers at both ends, and was merrily knocking away.

You should be able to check yours by pushing it into the engine and seeing if the noise goes.

 

[paulquinlan]

Thanks for the help guys!
Checked the 'two pistons' and they are fine.
Sounds like it may be the alternator free wheel clutch ........ will check it out.

 

[television]

Thanks for the help guys!
Checked the 'two pistons' and they are fine.
Sounds like it may be the alternator free wheel clutch ........ will check it out.

The alterator has not got a clutch, that's the air con pump. turn the air con on to min, and see if the noise goes

Malcolm

 

[tamrsoft]

The E220 CDi does have a freewheel clutch mechanism in the alternator pulley but I cannot say what other engines have it fitted. I have one on mine and it is seized and is causing excessive belt vibration at idle, its a classic problem. You can recognise whether this type of pulley is fitted by removing the plastic snap-on cover from the pulley and you should see a multi-splined recess in the front of the pulley to accept an extractor tool. Another cause of excessive vibration at idle is an EGR valve stuck open at idle, again I do not know what EGR system is fitted on the E300 but its worth a check.

 

[Big Eb]

alternator pulley morning all.

Morning all, got an e300 w210, need to replace the alternator pulley.

Is it best to remove alternator from car rather than try in situ.
Thanks, Eb