1994, C280: Metal dust on serpentine belt

[Arv]

Hi all:

Couple of months ago I installed an aftermarket (not OEM) engine belt which I purchased at a local auto store. Few days after installing, I started seeing the belt getting shinier. Now there is lot of metal dust on the belt from the outside, not on the grooves. I checked from under the car and it is making a groove in the engine fan pulley and that's where the metal dust is coming from. Now, FYI, the fan pulley doesn't have grooves, so the belt runs on it on it's flat side. If I press on the belt (to feel the tension) near the alternator area, I can press about 1 cm or so. I had never seen this dust on any of my previous belts.

Is the belt too tight?

or

Is the aftermarket belt too hard?

Thank you all for your help,
Arv.

 

[television]

I cant help on this sorry,,its an odd thing to happen

 

[Cole@MBS]

Bottom pulley losing its rubber insert maybe, common on that lump, eats into the engine casing!!

 

[television]

Bottom pulley losing its rubber insert maybe, common on that lump, eats into the engine casing!!

Yes and I think that it wobbles when running, so you can see that

 

[Arv]

Hi all:

Thank you for your replies. I am talking about the main engine fan pulley which is getting grooved by this belt. The belt runs on the pulley on it's flat side. There is no rubber on that pulley at all. I can see the pulley has become shinier about 1cm in the middle and if I slide my finger on it, I can feel that it has become rough and not smooth like it used to be for last 15 years.

Any other ideas?

Thank you all again,
Arv.

 

[Xtractorfan]

I think you may be talking about the idler pulley, it is possible that the bearing has gone in it, also possible that the outer surface has picked up some debris from the old belt .. a problem with some of the hard plastic pulleys...I would suggest that you remove the belt and check all the pulleys for lateral movement .. also possible to run the engine and check if all pulleys are running in line ... still agree with SAM tho'

 

[television]

This is the layout

http://www.detali.ru/cat/oem_mb2.as...GM=717.465&CT=M&cat=19X&SID=13&SGR=135&SGN=05

 

[Arv]

I should have posted this image a while ago. But here it is. You can see the shiny metal dust on the belt from the engine fan pulley. I can feel the pulley getting grooved in the center because of this wear. I just changed the engine mounts and will see if this problem will go away in few weeks. Tomorrow I will wipe the belt very clean and watch if metal dust reappears. If I roll my finger over the belt, I get the metal dust on my finger. May be there was some belt tension problem because all the mounts were completely, I mean totally gone. Will let you know.

The tension seems to be ok. I can press on the belt around 1cm or so between 2 closest pulleys. Also, I will try loosening the belt just a very little in case it's too tight.

Thank you all,
Arv.

 

[Arv]

Sorry for a very long delay in giving my feedback and learning experience. This might help someone else having similar problem.


I finally figured this problem out when I did the coolent pump job myself. This problem was because of WRONGLY INSTALLED TENSIONER NUT when my mechanic had installed new pump last time and lack of proper belt tension. For C280 at least, the nut needs to go from under the tensioner bracket with the BIG round end of the nut under the bracket (not sitting on the top of the bracket) as shown in the pic. So, when you turn the nut clockwise, it pushes the belt tensioner pulley away and tensions the belt. May be for some other models, it is the other way around.

 

[television]

Thanks for the update, nice to know.