CLS squeak noise at idle

[MWCLS]

Hi, Had the car serviced at MB 6 weeks ago and I haven't really driven it since what with the crappie weather plus I have a co car. I started the car today and noticed a squeak noise coming from the V belt area, without thinking and checking the pulleys were all turning etc i just sprayed a very small amt of wd40 near all 3 top pulleys and let her run for a couple of mins.

This instantly remedied the noise, have I just masked a potential problem? Looking on the net it could possibly be one of the pulleys on the way out, bearing in mind the car is 04/2006. Any advice or pointers would be much appreciated.

Regards


Michael

 

[MWCLS]

Just to add the car has full MB service history.

 

[Paparazi]

Very likely just a dry belt....the WD40 lubricating said belt...won't last long but you haven't harmed anything. Historically, there used to be a product called 'belt dressing' this was a sticky spray designed for this very purpose, not sure if it's still available.
Definitely worth having the condition of the belt checked because as with all rubber products they deteriorate with age, become hard and the multi v drive surface starts to show numerous small cracks.
Belts are cheaper than you might imagine.....look for Contitech brand.

Martin

 

[RAJ55]

Similar thing happened to my old w219 cls, turned out to be the v belt tensioner. Bought a new one for £35 and fixed the problem. The issue is identifying which pulley is at fault. What i did was get some water or wd40 and spray it on the pulley bearing (not the belt) and see if the noise goes away, if it does thats your faulty one. You can even use a mechanics stethoscope if you have one.

could be the belt as mentioned but as you said you have full MB service so its likey to have been changed. Good way to check is take the belt off and bend it so the ribs are facing up and see if there is any cracking.

If it is the tensioner, dont go to MB for it as i think it was about £80. You can get the same make much cheaper on the net. Mine was originally a 'gates' one. Also if you do take the belt off draw a picture so you know how it goes back on.

Raj

 

[MWCLS]

Very likely just a dry belt....the WD40 lubricating said belt...won't last long but you haven't harmed anything. Historically, there used to be a product called 'belt dressing' this was a sticky spray designed for this very purpose, not sure if it's still available.
Definitely worth having the condition of the belt checked because as with all rubber products they deteriorate with age, become hard and the multi v drive surface starts to show numerous small cracks.
Belts are cheaper than you might imagine.....look for Contitech brand.

Martin

Thanks Martin for the advice, I've sort of ruled out the belt as it's just been serviced, but I have checked it to make sure and it looks ok.

Similar thing happened to my old w219 cls, turned out to be the v belt tensioner. Bought a new one for £35 and fixed the problem. The issue is identifying which pulley is at fault. What i did was get some water or wd40 and spray it on the pulley bearing (not the belt) and see if the noise goes away, if it does thats your faulty one. You can even use a mechanics stethoscope if you have one.

could be the belt as mentioned but as you said you have full MB service so its likey to have been changed. Good way to check is take the belt off and bend it so the ribs are facing up and see if there is any cracking.

If it is the tensioner, dont go to MB for it as i think it was about £80. You can get the same make much cheaper on the net. Mine was originally a 'gates' one. Also if you do take the belt off draw a picture so you know how it goes back on.

Raj

Thanks Raj, I think your right on the one of the pulleys, I've checked the belt myself in situ, tbf it still looks new , no ribbing or cracking. I think I'll have it checked over a friend of mine is a ex Merc tech, my spannering skills aren't the best haha

 

[Paparazi]

Quote: Thanks Martin for the advice, I've sort of ruled out the belt as it's just been serviced, but I have checked it to make sure and it looks ok.

Belt has been 'serviced' interesting, what does that mean exactly?
Ahhh! they looked at it and said it was OK?

With the greatest of respect, it may well look fine but still be making a noise!

I'm not ruling out the 'tensioner' as a possibility but if you just squirted the WD40 generally in the direction of the belt it is much more likely that the belt is the cause of the noise.

How many miles has the car done...how old....is the belt the original?

Martin

 

[MWCLS]

Quote: Thanks Martin for the advice, I've sort of ruled out the belt as it's just been serviced, but I have checked it to make sure and it looks ok.

Belt has been 'serviced' interesting, what does that mean exactly?
Ahhh! they looked at it and said it was OK?

With the greatest of respect, it may well look fine but still be making a noise!

I'm not ruling out the 'tensioner' as a possibility but if you just squirted the WD40 generally in the direction of the belt it is much more likely that the belt is the cause of the noise.

How many miles has the car done...how old....is the belt the original?

Martin

Hi Martin, I quite agree with you, the gentlemen I bought the vehicle from bought it new and has a very comprehensive MB Oxford history, the car has just clicked 79k, he only used it 6 months of the year mainly used as a cruiser to his property in Italy, so the rest of the time it sat in his garage. The V belt was last changed around the 40k, so as you rightly say I'm beginning to think it's probably the belt. I'm going to pick up a new belt from MB on Friday and take the car to my mech friend for fitting. He is ex MB so knows what to check and hopefully it's a straight forward belt swap, the belt has probably degraded over time so sounds the obvious culprit. We shall see.

Thanks once again for your input, very much appreciated and merry Christmas.

 

[SavMan]

With the belt off, check the bearings on each pulley including the supercharger clutch pulley. A flat head screwdriver held against the bolt with your ear on the handle will act the same as a stethoscope.

 

[MWCLS]

With the belt off, check the bearings on each pulley including the supercharger clutch pulley. A flat head screwdriver held against the bolt with your ear on the handle will act the same as a stethoscope.

Thanks Savman, I don't have a SC weird I had the car out earlier and the ' chirp ' noise is very slight I sprayed water in turn on each pulley giving say 45 secs between each squirt, it would slience for 30 secs then return, beginning to think it's the belt that has degraded, I'm no tech and have basic spannering skills so it's off to the garage Sat morning, I wouldn't even attempt to remove the belt. I'd never get it back on haha.

 

[TDE1]

Interestingly (or not) I've just had a quote frm MB for an F Service. It included £73 to check poly v belt. Seems a lot.

 

[MWCLS]

I just had a B service £371.00 Inc £10 discount booking online 5th Nov 13 No advisories! ( due according to car and MB records ) which I believe is a quite a comprehensive check.....allegedly and i've only covered 50 odd miles since . So the V belt would have been checked.... according to electronic printout MB gave me. My next service is due in 9225 miles is service E, no idea what that entails, Im guessing it's like BMW condition based servicing.

As my thread title states, they must have just glanced in the general direction of the pulleys and belt lol