My 95 e300D has a loud vibration at idle. I traced it to the belt tensioner. If I put a pry bar under the tensioner shock absorber, it stops. So I figure I needed to replace this little shock absorber. Thought it would be simple task, but the bottom bolt would not come out with out removing the fan pulley.....which had its own set of issues. Anyway I replaced the little shock and the vibration is still there. It seems to be in harmonic with the engine idle. If I raise the idle just a little bit the noise goes away.

Any one else had this problem?

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1995 E300 Diesel
1994 E320
1999 C230K
1994 S500 W140
1990 300 SEL

Anyone?

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1995 E300 Diesel
1994 E320
1999 C230K
1994 S500 W140
1990 300 SEL

I had a similar issue come up after I replaced my alternator with a new one from NSA. The new alternator came with its own pulley, and I just swapped the entire altenator out with the old one. When everything was back together, I started it up, and ended up with the noise you describe. Replaced the little shock, noise still there. Then I decided to remove the pulley from my old alternator and put it on the new one. Noise was gone. After investigating further, I found out that the old alternator had what is called a "Free wheel clutch pulley" that compensates for the compression stroke of the engine. The new alternator pulley was just a plain pulley. If your model has a "free wheel clutch pulley" installed, and it has frozen, then that might be causing the noise. Hope this helps...

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96 E300d

hhhmmm, that's interesting. This car has 250K miles on it...and I have only put the last 5K on it....so it's probable the alternator has been replaced. Wonder if the pulley can be purchased separately?

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1995 E300 Diesel
1994 E320
1999 C230K
1994 S500 W140
1990 300 SEL

Does this look like the right pulley? This shows to be the OEM pulley.

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1995 E300 Diesel
1994 E320
1999 C230K
1994 S500 W140
1990 300 SEL

[QUOTE=agood;2719996]Does this look like the right pulley? This shows to be the OEM pulley.

Thats the one that came on the new alternator from NSA. Below is a link to the one that was on my old alternator.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=130153696583&crlp=1_263602_325002&ff4=263602_325002&viewitem=&clk_rvr_id=233481492219&guid=cf68a2a612b0a0e2029683c6ffbdd1c2&hlp=false&rvr_id=233481492219&ua=WXS%3F&itemid=130153696583

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96 E300d

hhhmmm, none of the suppliers I use show this pulley as an application for the 95 E300. Just curious if anyone else has this decoupler pulley on their 95.........

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1995 E300 Diesel
1994 E320
1999 C230K
1994 S500 W140
1990 300 SEL

makes sense - this is also the reason VW 1.9 IDI engines break their timing belt cogs on the crank, the alternator applies a brake to the crank which results in wear.

In our Benzes - if this pulley was used it would stop the belt from stretching/contracting - and overworking the tensioner. I also have that nasty tensioner rattle - I'll check the alt pulley

The tensioner pulley and/or arm is also a common failure.


FYI
The water pump on your engine has been superseded four times.
MB# 602 200 02 20





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So now we are saying the water pump is the problem...????

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1995 E300 Diesel
1994 E320
1999 C230K
1994 S500 W140
1990 300 SEL

I am letting you know the water pump was superseded = it could be a contributing factor or the main issue.

At 250K miles multiple issues are possible.

For a correct diagnosis you need to remove the belt, and check:
* The tensioner arm for looseness - slop.
* The tensioner pulley for looseness - slop.
* All pulleys for smooth rotation.

Tensioner arm, pulley and shock have all been replaced......

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1995 E300 Diesel
1994 E320
1999 C230K
1994 S500 W140
1990 300 SEL

checked mine in the parking garage - and its solid. So while going home yesterday - I stopped by this place which refurbs starters and alternators to ask for a clutch pulley and if they have seen one on this model of car, luckily the owner drives a 210 with OM606 - and he told me that he put in the clutch pulley because of the stupid vibration. According to him

He changed the engine mounts, belt, tensioner, arm and water pump - when his alternator gave up he rebuilt it with a clutch pulley and its been quiet ever since.

Can someone chime in that is the original alternator pulley on the OM606 a clutch type or solid..

I checked my shop manual, and it states that starting from engine number 602.982, 1/12/95, the alternator fitted did in fact have the free wheel clutch pulley as standard equipment.

When I went to change out the alternator on my 96E300d, there was a clutch pulley already in place. It was a Bosh alternator, and do not know if it was original equipment. I purchased the car used. Prior to putting in the new alternator without the clutch pulley, I did not have the noise. As soon as I put the new alternator in, the noise was there at idle, and there was a good deal of vibration in the belt itself. After transferring the old pulley to the new alternator, noise and vibration was gone. Up to that point, I had never even heard of a clutch pulley, but I learned something new that day.

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96 E300d

I used to own a diesel VW 1.9 - and because the older models did not use a clutch type pulley the timing belt cog would work the woodruff key loose wrecking the engine. btw this engine used a serpetine belt system like our cars. The older 1.6 diesel did not have this issue with V belt arrangement, The multirib serp belt transfers more torque compared to the V

Later TDIs used a D shape flat on the crank for the cog and a clutched alternator pulley to remedy this problem.