CLS Road Noise problem ...Design Fault!!!???

[Skull]

Hi, I'm new to the forum and to Mercedes Benz in general, having spent years on the dark side driving BMW's (eventually their love of runflats and rock hard suspension meant a change was needed!) So, I am now the proud owner of a 3 yr old CLS 320 CDI.

First impressions of the car are good, However I can hear a droning noise over 20mph which is in addition to the expected tyre noise from the larger 19 inch AMG wheels it has fitted. (Why do you never spot these things on the test drive!!). The Tyres are Pirelli Rosso's.

Anyway I was gobsmacked to be told by the MB Service Manager that the noise was down to turbulence between the tyres and the arches and that it was a known "issue" and was actually down to the design of the car... They have tried to fit sound proofing under the arches of some of their CLS's - where the owners have complained, but it has not worked very well. I just wanted to see if this was a well known issue, as I cannot believe CLS owners are happy to put up with this noise intrusion ...it drives me nuts and spoils an otherwise impeccable drive!

I may get an opinion from a different AD but any thoughts from other CLS owners would be most welcome.

 

[JerryC200Cdi]

I had a Toyota Celica Premium Red running on 17" alloys and low profile tyres and the road noise was so bad, particularly from the rear quarter panels and rear arches I had "Dynamat" put in all the rear panels and the boot. It did help, but then I too started to hear a droning noise. The dealer checked out the tyres to find that on one of the rears the treads had a "flat spot" and areas of raised tread or stepping which apparantly is common on rear tyres of FWD cars (or so they told me). I found over the 18 months I owned the car the roadnoise was so intrusive that I had to have the radio up loud on motorway/A roads, it drove me mad.

Road noise I think becomes part of the tradeoff of having larger and wider tyres.

My C200 CDi is a whole new level of quiteness compared to the celica.

 

[saorbust]

Don't hear it on mine - try changing the tyres to an MB spec. I have Conti Sport 3's - find them absolutely fine.

 

[Mactech]

My CLS is on MO spec Dunlop 01's and the tyre noise is only very small smidge more than the S Class which is the reference for low interior noise.
I had Pirelli on an SLK and that was really was was quite noisy with the roof up, but I never drove it on any other tyres.

 

[Sp!ke]

I also suspect tyres to be the cause.

You've not got Pirelli's on by chance?

 

[Brian WH]

I also suspect tyres to be the cause.

You've not got Pirelli's on by chance?

Yes he has - Pirelli Rosso's if you read his post.

Mine is running on 18" Continental Sports Contact 2's and although I have the wide rear tyres, which are a bit noisier than normal, I haven't heard the noise you are referring to. In fact my CLS is quieter than my previous E Classes.

Don't be fobbed off by the Dealer, tell him to sort it.

 

[Skull]

Thanks for the replies everyone, it is much appreciated. It is strange that my local MB dealer (not the dealer I bought the car from incidentally) is adamant it's turbulence created by the design of the cars wheel arches and yet I can find nothing relating to this on the net (you'd think if this was the case it would be well publicised!) I hope it is tyre noise from the Pirelli Rosso's as this can be rectified by a change of tyres ... otherwise it will be a short marriage ! :-( My only dilemma will be what to change them for. I suppose a softer compound may help?? Bizarrely, the droning noise is at its most noticeable at around 40-50mph. Ive also played around with the airmatic suspension settings but the ride height does not really affect it.

 

[Howard]

I have P Zero Rossos on the front of my CLK , i won't be putting them back on when the time comes to replace them. Very noisy.

 

[Simon_M]

Yes he has - Pirelli Rosso's if you read his post.

Mine is running on 18" Continental Sports Contact 2's and although I have the wide rear tyres, which are a bit noisier than normal, I haven't heard the noise you are referring to. In fact my CLS is quieter than my previous E Classes.

Don't be fobbed off by the Dealer, tell him to sort it.

Ditto, same tyres and presumably sizes (275 35 R18) on mine and it is OK. Bit noisy but not the speed related noises you describe.

Simon

 

[CLS]

Thanks for the replies everyone, it is much appreciated. It is strange that my local MB dealer (not the dealer I bought the car from incidentally) is adamant it's turbulence created by the design of the cars wheel arches and yet I can find nothing relating to this on the net (you'd think if this was the case it would be well publicised!) I hope it is tyre noise from the Pirelli Rosso's as this can be rectified by a change of tyres ... otherwise it will be a short marriage ! :-( My only dilemma will be what to change them for. I suppose a softer compound may help?? Bizarrely, the droning noise is at its most noticeable at around 40-50mph. Ive also played around with the airmatic suspension settings but the ride height does not really affect it.

Tyres and tyre size is important to noise...CLS is famous about for low interior noise.

But continental under your CLS.

 

[LTD]

Had Rosso Nero's on my Golf - sounded awful but gripped well.

Tyres make a huge difference on a Mercedes. Go with the suggested options and you will be spoiled.

 

[APM]

mines on bridgestones and isn't noisy,apart from the exhaust!!!!!!!!!!!!!!!

 

[Adam230K]

You can experiment by buying second hand tyres and putting them on to see if there's a difference. Continentals/falkens/goodyears are usually very quiet.

 

[camerafodder]

Are your tyres badly worn or do they display any uneven wear?

 

[soley]

Sounds like your dealer is bulling you ,mine has continental sport contact 2 fitted no noise at all,you could try test driving another one. The dealer should be only too happy to prove they all do it..!!

 

[Brian WH]

Sounds like your dealer is bulling you ,mine has continental sport contact 2 fitted no noise at all,you could try test driving another one. The dealer should be only too happy to prove they all do it..!!

Mine too no problems.

 

[The Pan Man]

Brian WH Just a question ref your CLS. How does the interior space comare with your previous E-Class cars?

 

[Brian WH]

Brian WH Just a question ref your CLS. How does the interior space comare with your previous E-Class cars?

The only difference is the headroom, which being small is not a problem to me. The boot is Ok too, but has less throat size to get the luggage into. It is wider and longer, but lower than the E Class. see below.

 

[Skull]

Once again thanks for the replies everyone. I thought I would post a further response, although it is slightly off the original topic. Unfortunately the road noise is now the least of my worries. I have been dogged by problems since buying the car a couple of months ago. It has been into the dealership 4 times in 8 weeks !!! If I did not like the car so much I would have rejected it back to the dealer... but now my patience is wearing v thin. Transmission type problems (The car would literally stop and jerk under hard acceleration) has led to the dealer replacing the lambda probe then the air mass meter and resetting the software... before I could see if this had resolved the issue an injector went rendering the car undriveable. I now have the car back and to be honest I am not convinced it is 100%, the gear changes are really clunky at times particularly downshifting when crawling in traffic or when accelerating hard from slow speed it just seems almost confused and unsmooth. I am at the end of my tether I am not sure if this is just the way they drive but I cannot believe it is. My previous BMW 530d was far smoother changing gears up and down. I will ask the dealer to provide another cls for me to try but I fear there could be an inherent problem with my box that is not easy to diagnose/fix... anyway rant over, as always I would welcome anyone's feedback and advice.

 

[Brian WH]

The gearbox should not be Clunky. I have had Two CLS's and no problems with gearboxes. However on my previous E Class the gearbox was Clunky and they reprogrammed the software and it was Ok when it settled into your style of driving, memory etc.
If it doesn't settle in a week or so get them to reprogramme it again with the latest software.