What parts do I need for belt tensioner problem? - PeachParts Mercedes-Benz Forum

guyever · #1 08-15-2004, 04:39 PM

The problem first appeared today as i was at a drive in restaurant and noticed some motor noise as i pulled up to the window. Thought it must be the guy behind me, but quickly discovered i had no one behind me so it must be me. Got home and popped the hood and quickly noticed a slightly wobbling tensioner pulley. Stopped the engine and saw a few, very small, shiney, metal flakes scattered about. I can wobble the pulley a little by hand. Of course my first action was to log onto ShopForum and see what you guys had to say. I did a lot of searching, learned a heck of a lot, but couldn't quite get the answers I needed. What parts should i order? do I need just a pulley, just a tensioner? what about the shock? I really need to get these parts here post haste so I'll need to order early tomorrrow morning. My guess is that it is just the pulley, but it would be prudent to replace everything as the car has 77,000 miles on it. Am I right?
Thanks
Guy

Gilly · #2 08-15-2004, 04:41 PM

Guy:
It sounds like the belt tensioner is bad, I've seen may of these fail. Luckily it's ALOT easier than the ones you've been reading about, cheaper too. I'd order up a belt tensioner, unless I'm way off track and it's something else.

Gilly

guyever · #3 08-15-2004, 05:13 PM

Thanks Gilly, I checked FastLane and it looks like about $175. Do you think I also need the pulley? I should have pulled it off and looked this afternoon, but I,ve been working on taxes that I extended last April, and just couldn't work it in.
Thanks again,
Guy

BenzRepair · #4 08-15-2004, 05:19 PM

If this is on your '98, The tensioner pulley contains a large spring for tensioning, instead of the troublesome rubber-sandwiched tensioner pulley mechanisms found on earlier engines (M102, 103, 104). Rarely see the mechanical spring tensioner assembly go out, but they are a very simple and uncomplicated replacement, compared to the sometimes nightmarish jobs that tensioner replacement of yesteryear required. You should not have to replace the entire tensioner assembly, just the pulley (very common), but it is easy enough to replace if you want to.

BenzRepair · #5 08-15-2004, 05:23 PM

Quote:

Originally Posted by guyever

Thanks Gilly, I checked FastLane and it looks like about $175. Do you think I also need the pulley? I should have pulled it off and looked this afternoon, but I,ve been working on taxes that I extended last April, and just couldn't work it in.
Thanks again,
Guy

Pulley should come with the new one -- good luck; requires E-torx to replace, but most auto stores carry a cheap set.

guyever · #6 08-15-2004, 06:01 PM

BenzRepair,
Thanks for your input. Yes this is on my E320. Have a great rest of the weekend.
Guy

Gilly · #7 08-15-2004, 07:32 PM

If you're positive it's the pulley ONLY, then I believe you can buy it seperately, otherwise the tensioner comes with the pulley, as already stated.

Gilly

BenzRepair · #8 08-16-2004, 12:06 PM

I cannot seem to find the pulley separate from the belt tensioner through conventional sources, looks like you will need to buy the entire assembly. Star Motors has it in stock for around $150 (800 STAR-LTD); sorry for the confusion. I know there's a pulley out there somewhere, and I will find it.

guyever · #9 08-16-2004, 06:15 PM

I really appreciate your replies on this, but I've got a confession to make. I think I may have over reacted to what I thought was a problem which turned out not to be a problem (or at least that is my current thought). I spend a fair amount of time reading various post especially those pertaining to W210's and I keep expecting the problems I read about to happen to me. The window regulator is a classic example. Been reading about it for some time now and lo and behold mine broke 2 weeks ago. I had read many post about the belt tensioner and when I saw mine wobbling yesterday I jumped to an incorrect conclusion (that mine was going to "come apart" any minute). I was so convinced that I called Phil (FastLane) this AM and ordered a tensioner (couldn't find just the pulley). I decided to take one more look at the "wobbling" pulley and discovered that it wasn't wobbling, but was rather moving in and out parallel to the belt. Took it to an indy around the corner and he said it looked fine to him the movement was as it should be.

Lessons learned:
1. All about tensioners (or at least a lot more than I knew)
2. You really need to accurately to describe the symptoms to get help on ShopForum, ie wobble vs. lateral movement.
3. Don't get too carried away with what you read and misapply it to your situation. (Ever read a medical book and decided that you had all of the diseases described there?)

All of this is not for naught, I will probably have to replace that tensioner someday. Keeping a close eye on the harmonic balancer and trying to keep an open mind about that! Special thanks to BenzRepair and Gilly. You guys are the greatest. Now I gotta go replace that window regulator; parts arrived today.
Guy