grizzly111

I recently picked up a chiping sound coming from the accessories belt on my w204 C250. Tested it with a spray of water - it went away. I diagnosed it as a belt out of alignment (car has only done 20000 miles).
Took it to the dealer & asked to investigate. They said yup it's the belt. But it's Mercedes Benz's policy that they don't do adjustments and that they will need to replace BOTH the belt AND the belt tensioner mechanism which they reckon is worn.

Cost quoted: $650 inc labor.

Does this seem right? Would appreciate some guidance.

ItalianJoe1

What "adjustment" would they do, according to your diagnosis?

grizzly111

Can't they check if the belt is misaligned and then re-fit?

ItalianJoe1

How exactly? On a system with an auto-tensioner? You say you diagnosed it, what did you find to be the root cause of the noise?

grizzly111

MY diagnosis is basic with the water spray method to rule out bearing noise. What you are saying is that there are no adjustments to be made on this vehicle and that the way to fix this is to replace the entire tensioner system as per Benz diagnosis. I can accept that but is the cost reasonable?

ItalianJoe1

The tensioner will be expensive from the dealer, it isn't hard to change but again, dealer labor is expensive. I'd assume about half labor, half parts, and at our rate of $180/hr, that sounds pretty normal

grizzly111

Appreciate the response. Do you have a recommendation for a non-OEM tensioner on the market (if any are available?).

NZ-Merc

Hi Grizzly111,
If it was my car I would have a good look at the belt with the aid of a torch to see if there is any visible damage to the belt, if all good smear a small amount vaseline on both sides of the belt in one spot to see if it goes away after starting.

Hopefully it will be no noise and does not return after a short run to confirm all is good, I have done this repair numerous times with no return problems and suspect some dust debris can get on to the belt and dry it out.

Your car has only done 20k so dont see why a bearing and belt designed for 150k plus milage should need changing definitely falls in to the over charging and changing parts for the sake of it.
Please try my recommendation and let us know how you get on.

Moto_Guzzi

Thats about what it cost me in parts to replace the Belt, Idler Pulley-1, Idler Pulley-2 and Tentioner myself.

grizzly111

Just thought I'd update this thread for the benefit of others - as it turned out I was correct in my diagnosis! But it wasn't entirely what I expected. I really did not trust the Benz dealership's diagnosis or price for that matter. So I took the car to an independent and they diagnosed it straight away. The belt WAS out of alignment BUT it was actually caused by a poorly fitted belt tensioner from factory. It was incredibly obvious to the tech once they got started. The entire tensioner was not bolted in correctly (ie: a couple of bolts were not tightened straight so the tensioner body was not sitting flush!). This caused the belt to be out of alignment which in turn caused the symptoms as above. Also I noted that the ECO light would rarely go green almost the entire time I owned the car. After the fix (which was simply removing & realigning the tensioner + new belt) no more noise, the ECO light goes green frequently and all is fine.

pezzy669