Airmatic and Tracking/Balancing....

[PJayUK]

I still have a slight rumbling noise from the offside front of my car, that is most noticeable when the car is cold. So far I have replaced the front discs and pads, had 4 new tyres fitted, the rear diff oil changed and the suspension etc checked by my local indi. Nothing was discovered, but he did experience the noise first hand which is good.

Tracking and balancing is on my list of things to try next, so as always I have a couple of questions that I am hoping for some help with.

1 Does anyone have any general advice on where to go and what to request (ie, laser tracking, dynamic balancing etc)
2 My car has Airmatic does this require any special consideration or does it need to be done at an MB friendly establishment
3 When I had the tyres replaced the the car had dropped and the Airmatic warning (too low etc etc) was on. It raised after about 10 seconds, is this normal?
4 I had Nexen N6000's fitted all round as money was a little tight. There is more road noise that the previous very cheap, very worn tyres that were on. Will they settle down and get quieter once they bed in a little?

As always any help and advice greatly appreciated

 

[television]

Suspension component are not affected, and are neither hot nor cold items. The steering box and power steering pump are off side things and these can be affected by hot and cold

 

[jberks]

4 I had Nexen N6000's fitted all round as money was a little tight. There is more road noise that the previous very cheap, very worn tyres that were on. Will they settle down and get quieter once they bed in a little?

Tyre noise is generated by the air squeazed out through the gaps between the tread. As tyres wear, the tread depth is reduced and so the amount of air trapped and noise produced reduces. So the simple answer would seem to be yes.

 

[PJayUK]

But doesn't the W220 have rack and pinion steering rather than a steering "box"?

 

[Xtractorfan]

Actually some brands of tyre get noisier (more hum) as they wear down..good from the point of view that a lot of ppl who drive upmarket motors would never check tyres or brakes but will notice noise differences..

 

[Xtractorfan]

But doesn't the W220 have rack and pinion steering rather than a steering "box"?

Still got power steering and and belt driven pump

 

[television]

But doesn't the W220 have rack and pinion steering rather than a steering "box"?

Indeed it does, but there is still the hydraulic part for the power assistance

It would be very easy to open the bonnet and have someone just pull the steering wheel a little, while you listen for any sounds.

Re tyre noise, the big V shaped treads are often noisier than the conventional smaller tread patterns.

 

[PJayUK]

Nexen's I had fitted are the newer type N6000's. They do seem to have big V shape tread. Maybe I am being too critical but I expected the SClass with Airmatic to be quieter than mine is. There is certainly road noise that is surface dependent, and worse when wet.

Maybe I need a Rolls!

 

[television]

Maybe I need a Rolls!

They can be very hard on the wrist, really painful :wink:

 

[PJayUK]

I definitely think this is road noise. I spent my whole journey in to work today (around 30 miles) with the radio off listening to my car as we traveled over country lanes, A roads and the M25. There is a very noticeable level of road noise or tyre roar that is surface dependent. On some parts of the M25 the ride is silky smooth like being transported on a conveyor. On other sections though I can hear a distinct roar from the tyres. On particularly bad sections there is even some vibration feedback through the steering wheel.

There are no issues with the cars stability or handling and as I mentioned it has been checked recently. Its just not what I expected from an SClass with Air Suspension, I thought the ride would be more cushioned from this kind of thing.

Not sure there is a fault as such and perhaps I am being overly critical but would this be considered normal? Would having the tracking help things or should I wait and see if my new tyres quieten down after a 1000 miles or so?

Malcolm, any views??

 

[television]

It would appear to be tyre noise after what you say above.

I do know that V s type treads can be noisier than the finer patterns. Avon used to market a tyre with the same patten, and I complained and got them replaced with a newer version, but after a few thousand miles the went very uneven and noisy, and I went over to Dunlops

Here is one review that that gives the noise 3 out of 5 many other test give noise 3.5 to 4 out of 5

But it is a very hard controversial subject.

http://www.blackcircles.com/tyres/nexen

Do a search tyre reviews

 

[PJayUK]

Thank you as always Malcolm for your advice, its appreciated.

I dont think laser tracking will help this much, I'll live with the tyres until I can afford to buy some better quality ones. Noted your comment about Dunlops.

Still loving the SClass, it makes my Jaguar XJ8 feel like a piece of agricultural equipment even with cheap tyres!

 

[television]

Thank you as always Malcolm for your advice, its appreciated.

I dont think laser tracking will help this much, I'll live with the tyres until I can afford to buy some better quality ones. Noted your comment about Dunlops.

Still loving the SClass, it makes my Jaguar XJ8 feel like a piece of agricultural equipment even with cheap tyres!

The other thing is that our roads are awful, as regarding noise.

Yes I am an anti noise fanatic, I took my SL to Sweden last year, the roads are like silk and never a bump, no noise, it was like driving on a carpet, and that included Germany.
Only last week, out in the SL (230 with hydraulic suspension) I though how noisy it was.

I am not sure but I think that the Swedes use ground up old tyres mixed into the ash felt, we never re surface and use what ever the council can buy cheap, in order to keep their pension fund intact

 

[PJayUK]

Your dead right there is a section on the M25 just before the M40 junction 16 where it feels like they have used a piece of steel to join to parts together. The car makes an almighty judder when it goes acrosss (Its awful in my Subaru!)

On another note what I am going to change the oil and was wondering what you would advice as the best option for my SClass? Its done 118K and I want to treat her to the best I can put in. My local MB Indi suggested I steer clear of Mobil1 as its too thin, I would value your experienced opinion Malcolm!

 

[television]

I have answered in the oil post

 

[PJayUK]

Super thanks Malcolm.

I found out something odd about the heated mirrors on my SClass this morning too. It was 1.5 degrees when I started the engine and the mirrors were frosted. I left the car running for a few mins whilst I scraped the ice off and noticed that the wing mirror that I replaced over the weekend remained frosted over. Touched it and it was stone cold.....I cursed the damn thing!

Pulled away and it was clear and dry as a bone within 5 minutes, so they must only work when the car is in motion or in gear. Dont know what the contributing factor is but they dont seem to work when stationary. When I got to work I felt it again and it was toasty warm!!!

Very odd design it seems