OM651 serpentine belt adjust?

[ChrisHGTV]

Hello all

My S212 E250 is certainly wanting some attention from me at the moment! Apart from a normal B service its had a trans cooler and water separator(?) and im about to replace the DPF pressure sensor which the iCarsoft found a fault with.

However, for a while i have intermittently had a problem losing power steering, and it seemed to coincide with splashing through (not deep) puddles. I thought it might be a case of the belt slipping but nothing else was coming up with any fault codes, and to be honest it seemed unlikely as the belt isn't really near a particular splash zone that i could tell. However today i definitely heard a small squeak after a momentary loss in the rain, so assume it must be the belt slipping slightly.

So my question is - is adjusting the tension quite straightforward or does it need to have some critical tension? Also, would it be worth getting the belt changed/idler/tensioner changed? I read somewhere that a slipping belt can indicate impending doom!

Im off to the NL in it next month so trying to sort these niggles.

Thanks!

 

[ernie]

Hello all

My S212 E250 is certainly wanting some attention from me at the moment! Apart from a normal B service its had a trans cooler and water separator(?) and im about to replace the DPF pressure sensor which the iCarsoft found a fault with.

However, for a while i have intermittently had a problem losing power steering, and it seemed to coincide with splashing through (not deep) puddles. I thought it might be a case of the belt slipping but nothing else was coming up with any fault codes, and to be honest it seemed unlikely as the belt isn't really near a particular splash zone that i could tell. However today i definitely heard a small squeak after a momentary loss in the rain, so assume it must be the belt slipping slightly.

So my question is - is adjusting the tension quite straightforward or does it need to have some critical tension? Also, would it be worth getting the belt changed/idler/tensioner changed? I read somewhere that a slipping belt can indicate impending doom!

Im off to the NL in it next month so trying to sort these niggles.

Thanks!

The serpentine belt has an automatic tensioner, so if the belt is slipping, either the tensioner is faulty or the belt is worn out, or a combination of both. I would be prepared to change both, particularly in view of your tour to the Netherlands.

I would also check that there is no undue noise from, or stiffness in the other auxiliaries whilst the belt is out.

Ernie

 

[ChrisHGTV]

The serpentine belt has an automatic tensioner, so if the belt is slipping, either the tensioner is faulty or the belt is worn out, or a combination of both. I would be prepared to change both, particularly in view of your tour to the Netherlands.

I would also check that there is no undue noise from, or stiffness in the other auxiliaries whilst the belt is out.

Ernie

Good shout - this is what I’ve been thinking just for peace of mind!

 

[ChrisHGTV]

Well, a very enjoyable and (dare I say it!) successful morning! I changed the Dpf pressure valve and reset it using the icarsoft. Then changed the aux belt and tensioner. I checked all the other pulleys and they were all good. The belt itself seemed fine but changed it anyway. I have a feeling the tensioner was actually the cause. It still had some spring pressure but the new one was much stronger. It was actually a joy to do such a simple job, with plenty of space available. My only slight gripe was that I ended up paying through the nose for the bits as I got the belt and tensioner from ECP, about twice the cost of Autodoc. But I wanted to do it today, so that’s my fault! All fault codes gone and the car drives beautifully. I’m very much liking my new Bridgestone Turanza 6s, they’re definitely quieter than the Eagle F1’s. I do love the S212, even though it’s cost a fair bit to keep in good shape! It’s a nicely engineered car when you look at how it’s put together, it’s just some of the components are a weak point, but then I guess Mercedes don’t manufacture those bits that have failed.

 

[m80]

So a good spare belt to be carried, just in case.