paulv

I posted this for someone on the other forum. Hope it can help others here.

Enjoy..........


Regards,
paul...

starbrite

Excellent write up Paul !! Thanks.

Did you change it because you were getting noise from the pulley(s) or some play when you wiggled it ?

paulv

You're welcome!! I went ahead and changed it because the car had ~98,000 on it and I wanted to inspect the belt. Once the belt was off, I hand spun the idler pulley and there was some bearing noise. I put the old belt back on and ran the car at idle and checked both pulleys for noise with my stethoscope -- the idler had enough noise to warrant replacement and there was some noise from the tensioner, but the tensioner was oscillating (especially with the AC on) so the damper inside the tensioner was wearing out. It was time to replace everything!

Regards,
paul...

starbrite

Ah, yes, I forgot to ask the mileage on the car. Thanks

~98k is certainly a reasonable life expectancy for a pully/tensioner of this type. So, MB did a good job here.

If I may ask, what was the cost of the parts ?

And, lastly, a little OT, what progarm did you use for the write up ?

SPNJHockey

Great job, Paul. Thanks alot for taking the time for us DIYers.

paulv

I bought the parts from MB of Westchester OH -- MBWorld has an account there -- the parts mgr is Rob Lewis (513-870-1030 or 1004). I buy all my parts from him -- great service & prices. The parts total came to $268.

I used Microsoft Word to do the write up-up and then output it to pdf to cut down the size of the document.

No problem -- I'm a DIYer too, and appreciate people's help from these forums!!

Regards,
paul...

starbrite

Thanks for the added info paul, and the parts ph #.

SPNJHockey

WHOA...probably one of the cheapest mechanical-repair DIYs going! That's gotta be a grand at the dealer too.

gnma

PaulV's posts are awesome. Tks. for sharing.

werewolf34

Very cool. Thanks for contributing. What is it with MB and their love of Torx heads?

paulv

Many companies are using Torx head bolts now, not just MB. Time to make room in your toolbox for T&E type Torx. Suggest for the T numbers, you buy the security ones as you can use them for both secure and non-secure fasteners.

Regards,
paul...

Zaphodsplanet

I know this is an old post but it was very helpful for me. My W211 has about 117K miles on the clock and I figured I would replace the serpentine belt for good measure... though it really didn't look all that worn. My tensioner seems fine but I think I'll replace the pulley as it feels a little worn. I was having a hard time seeing where the nut was to take the tension off the tensioner.... your write up was super helpful. Thanks again.

Z

bigbudha

vettdvr

I replaced my belt at 88,000 and found the idle pulley bad also. I bought a replacement from Autozone and it had a bearing made in China. I looked at the OEM MB puilley I took off and it also had a bearing Made In China. Now at 120,000 the AZ pulley is still going. The AZ pulley was about $18.00 if I remember correctly and the MB part required either mail order or drive 100 miles and pay more. The car turned 120,000 miles yesterday and now the starter drive is squeeling after the starter disengages. Off to buy a starter.

hutchinshouse

Great write up! I just got a 2007 E350 with 124,000 miles. I'll be doing this DIY this weekend. If properly torqued, is Loctite or any other tread lock required? Thanks! Glad to be back in a Benz! :-)

MercFiveHundred

Great write up. I just did mine at 220k miles. Yea i know, way overdue. I bought all the replacement parts from my Mercedes dealer, but noticed the wheels on the new idler and tensioner were more plastic feeling than the original. BTW, both bearings were noisy and replaced. Another note, the tensioner is Litens brand, which is only $122 at autohaus (Autohaus says Mercedes brand is $224??). I bought it at $175 (discounted) from the dealer and same Litens brand.

Question: The new belt grooves looked smaller than the old belt (old belt had no cracks). My guess is that the old belt looked the same new and just wore down. Is that right? And with the belt grooves diminished, does that mean there will be 'hydroplaning' when the belt spins at higher speeds?

Merry Christmas and Happy New Year everyone!

emitch1

This thread was so helpful! Thanks so much! HOWEVER, I got the belt on perfectly and then started the car. The tension pulley is completely locked. What would cause this? Will replacing it fix the problem? Are after-market pulley assemblies O.K. to use?

Thanks!

Eric