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S211 alternator belt flapping...continued

ksareen

Active Member
Joined
Jul 8, 2011
Messages
83
Car
Mercedes E220 Estate Avantgarde
Hello all,

I described my problem a few months ago at the following thread:
http://www.mbclub.co.uk/forums/engi...cdi-alternator-belt-flapping.html#post1769025

It never got fully resolved and the car has had a new tensioner again yesterday after the piston on the previous one (3 months old) started leaking. But the belt is still vibrating around the alternator and there is still vibrating movement at the tensioner itself.

I've also changed the belt with 6PK2241 which I believe is 2241mm long, the one that came with the car was 2245mm. Having checked with online suppliers, 2241 is the right size.

Also the car is meant to have a solid pulley against clutch type(it already has a sold pulley installed), so don't know what else do now to resolve this problem.
When the steering is moved at idle rpm, it sometimes makes a squealing noise which is more pronounced when the steering is at extreme ends (makes the pump stop/ belt slip as well on its pulley).

My local mechanic has checked the pulleys for play and he said they seem OK! (I could sense very minor play on 2 pulleys but he said that's fine).

He has suggested 2 things:
1. Get an even shorter belt than 2241mm!
2. Get the car on STAR system and raise the rpm by 50-75. The idle rpm at the moment is showing at 775 as far as I remember. Once the rpm is raised slightly, the tensioner movement stabilizes considerably. Also the engine vibrations seem to get lot better when he raised engine rpm slightly via accelerator pedal.
Any other option like replacing pulleys would be expensive he says.

Can you please suggest what would be the best bet here? If a video is required, please let me know and I will upload.
The VIN is WDB2112062A324764.

Many thanks for your help in advance..
 
So you will go to MB dealer and buy a pulley for your car reg/vin and he will get you the correct pulley. You will fit /have fitted the proper pulley and your problem will go away. The belt will stop hopping and the noise will stop. MB pulley on my car was retail €165 +vat From alternator shop it was €90. Cheap just won't last he said.
 
Danny, What pulley would you like me to buy?
Is it the alternator pulley? If yes, my car needs the solid type, not the clutch type. The new alternator pulley at MB dealer is only around £20-£25.
Since my car has already got a solid pulley installed, do you think I should replace it with another new solid pulley bought from a MB dealer?
 
Hi guys I'm still new here but you seem to have the same problem I have with the tensioner, I'm 2 tensioner sand 2 belts in already! Toolman1954 replied to my post with an idea of replacing the alternator as this was where the fault lay for him, I think it's worth a try as I can get one for a good price from euro car parts or similliar. Hope this helps.
 
Thanks John. I've checked your thread. the advice is along the lines of clutch failing on the alternator pulley, but my alternator has a solid pulley, not a clutch one. so do u think i should still replace the alternator or pulley?
What does a damper do? How do I check if my car has one?
 
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Why is the belt vibrating round the alternator? Surely that's the important question? Has it partially seized or has the shaft bent?

You need to remove the belt and spin everything on the belt to find the problem

Nick Froome
 
if your car is fitted with a 1 way alternator pulley take the belt off and make sure you can only turn it one way.

They are very common.
 
It seems to me you should have a clutch pulley. When it seizes it makes it look like the tensioner is hopping about. Yes i mean the one on the alternator
 
Hi, I've checked with MB again, they said they would not advise to put a clutch pulley as from my VIN, I am supposed to have a solid one (which is already installed).
The belt seems to vibrate on the alternator pulley as well as there is vibrating movement on the tensioner. I will get a video and upload.
About the "1 way alternator pulley", can MB advise on that from my VIN or do I need to get the belt taken off?
 
There's not rubber granules adhering to the 'flat' side of the belt by any chance? This happened to mine when I used a non-standard belt and where the reverse flat side came into contact with the tensioner caused it to run 'bumpy' and vibrate.



.
 
And I remember someone has troubles with belt which had a different v-profile than in original ones.
 
Hi, This is a new belt now OE spec Dayco & a new Dayco tensioner. I can see that there are no rubber granules and the reverse side does not come into contact anywhere when the car is running (would also have scratches to prove otherwise).
There is no malfunction reported in the cluster and as soon as rpm is raised slightly it becomes super smooth.
Should I just buy a new alternator solid pulley from MB dealer as that seems to be a common culprit?
 
OK. On a 300 engine the smooth face of the belt runs round the tensioner so I just thought....

It was me ^^ that got a non OE belt with the wrong profile V's and the rubber particles that were shed got onto the smooth face and caused it to vibrate badly.



.
 
Hi mine was cured by an aftermarket damper which has totally stopped any vibration in the belt and the tensioner, funnily enough the engine and tensioner had the brackets to accept it even though the car was 15 years old at least and didn't have one fitted from new. It looks like a small shock absorber and works like a charm.
 

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