[XXXX]

If it is both sedan and touring who have this noise problem, is there for sure a solution. Because I have driven sedans with M and they were very silent. I also heard from people who have touring that they don't have any noise. Maybe they are not so sensitive, but if their cars really is silent it must have been a change in production. As I understand so have we all got cars produced in september/october?

[clausmoll]

Originally Posted by XXXX

If it is both sedan and touring who have this noise problem, is there for sure a solution. Because I have driven sedans with M and they were very silent. I also heard from people who have touring that they don't have any noise. Maybe they are not so sensitive, but if their cars really is silent it must have been a change in production. As I understand so have we all got cars produced in september/october?

Mine is a September production

[XXXX]

Originally Posted by clausmoll

Mine is a September production

Do you know when in September? Mine is produced in October.

[clausmoll]

Originally Posted by XXXX

Do you know when in September? Mine is produced in October.

Yes. 17th of September

[Zante]

Mine is also produced in september, but tody I tested a G21, almost similiar to my own but with adaptive suspension. It was much more quite but I could still hear the sound. It was a august production

[HighlandPete]

Have you guys, with the problem, established if it a wheel size, even wheel style related issue? Some early posts were trying to establish if it is wheel (more than simply tyre) related.

Reading through the topic, I'm not seeing that wheels have been eliminated, when it is clear some have a different sound levels on different surfaces, that does indicate wheels are involved in some way.

Depends what is generating and/or amplifying the sound, and what route it is transmitted to the cabin. Is the transmission air-borne, or has it a structural path? Even if it is not the tyres, it does appear the sound generated from different surfaces (changing levels) does get involved with the resulting sound track.

M-sport dominance (different suspension frequency) indicates a structural transmission to the cabin, hence why wheel bearings have been suspect and changed. Many wheel bearings are declared a problem with noise problems, when it is nothing to do with the problem, a wheel/tyre generated noise often mimics a bad bearing sound.

From an outsider's perspective, trouble shooting is the hardest thing to do with problems like this. 'Hands on' is the only way I've ever solved difficult problems in the past, when I was in the trade. You have to think laterally. Is it something simple like a wheel arch liner, or a heat shield, free to resonate with the wheels and/or air flows as speed builds up? Or simply stressed some way and acts like loud speaker, transmitting the sound to the body. Adjust or 'damp' the component and no amplification takes place.

Similar issues happen with engine acoustic covers, if they are not fitted correctly (or stressed), can generate some pretty strange engine notes and vibrations at specific rpms.

Following this topic with interest, now that I've read it through.

[XXXX]

If I try to summarize what has been written here and what my dealer told me, this it what we know so far:

1. It doesn't matter what kind of wheels you put on, or if it's summer tires, studded tires, RFT etc. The size or model of rim doesn't matter either.
2. Some have replaced wheel bearings and the sound is still there, but can also have changed a little bit.
3. It is only Touring who have this problem here.
4. There are several sedans that don't have this noise. Maybe all.
5. Bmw says that it's seems to appear only on M-chassi cars
6. The sound starts from 40 km/h or something around that speed. Not so much speed related otherwise
7. The oldest car so far is from August, but that one was quieter(?) and had adaptive chassi. Most cars here are produced in September/October.

This is what I think should be very interesting:
1. Has anyone driven a touring with m, that doesn't have this noise? And if so when was it produced?
2. Has anyone driven a sedan that have it? And if so when was it produced?

[Yossi123]

Originally Posted by Zante

Mine is also produced in september, but tody I tested a G21, almost similiar to my own but with adaptive suspension. It was much more quite but I could still hear the sound. It was a august production

Mine is 330i G21 m-sport with x-drive and adaptive suspension (October build) and I definitely hear the extra noise. Cannot compare the intensity to other configs but if it is louder in your cases than it must be REALLY bad.

[Zante]

Originally Posted by Yossi123

Mine is 330i G21 m-sport with x-drive and adaptive suspension (October build) and I definitely hear the extra noise. Cannot compare the intensity to other configs but if it is louder in your cases than it must be REALLY bad.

It was not so noisy as mine but it was definitely not so quiet as my friends G20. The same kind of sound was there, but I think it’s more annoying in mine. Maybe because it’s mine It could also be because that car was an earlier production.

[XXXX]

Here is a POV of G21 with m-chassi. The test driver mentions, several times, how quiet it is. "No road noise and no wind noise". I have been listening with headphones and I can't here the sound that I have in mine. If there are G21 out there that doesn't sound, then BMW probably know how to solve it. So lets speed it up BMW!

[Glaede]

Mine is still at the dealer and haven't heard if it helped using the base model struts/suspension setup. Since I haven't heard I guess it didn't

[530iDriver]

Has anyone thought about the possibility of this noise coming from the transmission?

[Glaede]

Originally Posted by 530iDriver

Has anyone thought about the possibility of this noise coming from the transmission?

Yes, I have.. Also due to the sound recording I did where it, to me, sounds like the noise is there in idle too. I'm not much into automatic transmissions, so I'm not sure if anythings is rotating/moving in idle inside the transmission?

However, it seems like the dealer doesn't really believe its related

[clausmoll]

Originally Posted by 530iDriver

Has anyone thought about the possibility of this noise coming from the transmission?

All possibilities are open at the moment

[530iDriver]

Originally Posted by Glaede

Yes, I have.. Also due to the sound recording I did where it, to me, sounds like the noise is there in idle too. I'm not much into automatic transmissions, so I'm not sure if anythings is rotating/moving in idle inside the transmission?

However, it seems like the dealer doesn't really believe its related

I get that.

If you do hear the noise, however faint, in idle is the transmission in drive or neutral?

How about driving with the windows down in a quiet road or parking lot?

To me noises that seem to develop at specific speeds and seem constant in nature, I always suspect either the transmission or rear differential. I believe your service departments are simply throwing out darts in the dark to see what sticks and what doesn't. Changing tires and bearings to your heart's content is not goin g to solve the problem as evidenced by this discussion.

[XXXX]

I have suspected the transmission or the diff from start, but then the sound also should be on non m-sport, shouldn't it?
Me and my wife took a walk earlier and a G21 (m) drove by us and we both thougth we heard the sound from it. Have you heard it from outside your cars?

[530iDriver]

Originally Posted by XXXX

I have suspected the transmission or the diff from start, but then the sound also should be on non m-sport, shouldn't it?
Me and my wife took a walk earlier and a G21 (m) drove by us and we both thougth we heard the sound from it. Have you heard it from outside your cars?

Are the affected cars RWD and/or AWD (X Drive)?

[XXXX]

Originally Posted by 530iDriver

Are the affected cars RWD and/or AWD (X Drive)?

Yes, both.

[Yossi123]

Originally Posted by 530iDriver

To me noises that seem to develop at specific speeds and seem constant in nature, I always suspect either the transmission or rear differential. I believe your service departments are simply throwing out darts in the dark to see what sticks and what doesn't. Changing tires and bearings to your heart's content is not goin g to solve the problem as evidenced by this discussion.

Whatever is causing the noise, the triggering factor is the type of the surface. On 95% of the asphalt roads the noise is present. But I have a specific two lane road, the lanes are made from different types of asphalt. On one lane, made from older type asphalt (very smooth, shining when wet type) the noise is almost non-existent. But on the other lane made from different type of asphalt (more grippy) the noise starts immediately.
I noticed that also on pedestrian crossings, when you drive on the zebra marks, made from very thick paint, the noise stops.

[XXXX]

Originally Posted by Yossi123

Whatever is causing the noise, the triggering factor is the type of the surface. On 95% of the asphalt roads the noise is present. But I have a specific two lane road, the lanes are made from different types of asphalt. On one lane, made from older type asphalt (very smooth, shining when wet type) the noise is almost non-existent. But on the other lane made from different type of asphalt (more grippy) the noise starts immediately.
I noticed that also on pedestrian crossings, when you drive on the zebra marks, made from very thick paint, the noise stops.

I don't think that it is the tires and the surface that make the sound, but different surfaces make different vibrations.

[HighlandPete]

Originally Posted by XXXX

I don't think that it is the tires and the surface that make the sound, but different surfaces make different vibrations.

If the surface is the common denominator, whether tires are directly involved or not, there is something inducing the noise/vibration at different levels, associated with the surface finish. (I'm still not convinced wheels/tires are not at least partly involved in generating the soundtrack).

The comment about M-sport model is also of interest. Thinking out of the box, is there something different about the underside of the vehicles? Particularly Tourings? Any different air flow deflectors? As M-sport models run lower to the surface, I wonder if that is involved in changing the harmonics of something fitted under the body.

Thinking back a bit, there have been reported issues with the engine undertray (or associated plastic parts) on the odd F3x models, where users have identified badly fitted (possibly wrongly fitted) parts which generate additional noises than when correctly fitted.

[HighlandPete]

This is a long shot, but could the part No.2 Aero cover panel (in the parts diagram) be a problem on some Tourings, be contributing the noise and vibration.

I know what I'd be doing, if I was trouble shooting this issue, I'd remove them and see if there is a difference. Could be acting as an amplifier, if there is a connection due to poor alignment, distortion, or some other problem with them.

BTW, the illustration is for the G20, G21 is not yet showing on RealOEM.