[Skyhigh]

Either way, my curiosity is triggered. I took some photos behind the wheel. Whilst I don't have that cover either, I noticed what may be a substantial difference.

Left is the OP's photo. Right is my photo.
Notice the different location of the bracket holding the brake pipe...!



This could be due to xDrive or something else. I wonder if the plastic cover would still fit!? The photo is from an angle, so there may or may not be sufficient space behind it...

[sillyluke]

Road noise on my 328i has been bothering me a lot. I've seen some videos of people just covering the hole with some tape but I'd rather use the part.

Are you able to share the link where you bought it from? It does not seem to open it for me properly when I press on the part's number.

I'm in UK. Would very much appreciate it!

[tiw30]

Sillyluke
Just write down the part number and take it into your nearest BMW dealer, the link will only take you to real OEM, or alternatively do a search on Ebay using the part number you may get lucky

Skyhigh
The only difference is the angle the wheel is turned at if the OP's wheel was turned less you would see the bracket holding the brake flexi as it is held by the bolt through the hub carrier note the difference in position of the drop link the OP's is further round.

My own car is an Xdrive and I have checked it and an Sdrive and they are both the same and the bracket does not impact the fitting of the cover

[Skyhigh]

@tiw30

Thank you for confirming.
My point was that the bracket holding the pipe is at a completely different location - as you can see mine is immediately under / to the left of the opening, between the 2 circular plugs (located diagonally), whereas in OP's case it is further down. This is also visible from the shape of the pipe. Can't see how this has anything to do with wheel turning

Or are you saying this bracket is not attached to the structure behind, as it looks on the photos…? (It was difficult to see, I only squeezed in the phone to take a few photos)

[tiw30]

If you follow the bracket you will see it secures the flexi hose to the strut and is held by the pinch bolt that holds the strut to the hub carrier, The OP's picture is also taken higher up and closer so it misses out a lot of detail yours has, trust me if his steering was turned as if he was turning tighter left you would see the bracket, you can also see the end of your flexi where it is mounted to the body clearly on the left hand side of your photo, it then travels over to the strut and is attached by the bracket you have marked with the arrow

[Zheez]

I haven’t bought this yet but I saw on the article page that it says it’s for LCI only. My car is 2014 so obviously pre-LCI. Anyone know what’s different about the pre-LCI models to make this not fit?

I’ll have a proper look at mine tomorrow if it ever stops raining here. May just end up putting a small amount of expanding foam in

[radoslavp]

Originally Posted by Zheez

I haven’t bought this yet but I saw on the article page that it says it’s for LCI only. My car is 2014 so obviously pre-LCI. Anyone know what’s different about the pre-LCI models to make this not fit?

I’ll have a proper look at mine tomorrow if it ever stops raining here. May just end up putting a small amount of expanding foam in

I'd be surprised if it doesn't fit. The bare chassis of pre and facelifted F30s are not changing so the hole must be identical in size.

[howe9191]

Ok I've tried this way, filled the gap with old socks, on both left and right side(the other side with metal cover), result is no difference. No significant in noise reduction. Tested with sound db tester, 65~70 dB at 90kmh same as previous.

Bear in mind my car has also soundproofed wheel arc previously.

[Jvac]

Originally Posted by Billfitz

I'm way beyond skeptical, and I'm an acoustical engineer. That said, my F34 is very quiet. I have no problem carrying on a conversation at 80 MPH. Perhaps being intended as a relatively inexpensive limo for the Chinese market it has better insulation than the F30. I know from looking that the insulation under my carpet is substantial, literally twice the thickness of that in any car I've owned before. Maybe that's why I never have to run my sound system at more than 80% to be obnoxiously loud.

Anyone in an f30 that has pulled up the carpet care to offer a comparison? I believe the "road noise" is tire roar in my case. I already made a big improvement in reducing wind noise by installing the oem foam strips in the door gaps. What I'm left with is tire roar which can be obnoxious in some cases. After reading the various threads on the subjects, I'm left to wonder what really can improve the situation. Most of the remedies I saw were costly or had questionable results. Am I missing anything guys? I suspect the bulk of the noise comes through the floor or wheel wells, but how best to combat it is the question.

[Billfitz]

Tire noise is primarily conducted through the air, because rubber is a natural acoustical insulator. Run Flats conduct more noise through the tire itself because of the extra sidewall material that's also stiffer than regular sidewalls.
Combating noise can be done two ways. One is to cover the sheet metal with vinyl mastic. I use this myself: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I haven't bothered to take out all the carpet and liner and put it on the sheet metal underneath, but if you want the car as quiet as possible that would be the first step. I have put it on any sheet metal that I exposed in the course of doing other work, like in my doors when I had the liners off to install true crossovers between the midranges and tweeters. Noise doesn't go through sheet metal, but rather the sheet metal vibrating is a source of noise. Adding mass with vinyl mastic reduces the vibration and therefore noise levels go down.
The next line of defense is to absorb noise once it's in the cabin. That's where heavy felt carpet underlayment comes in. The liner in my F34 is a full half inch thick.

[Skyhigh]

Fully agree. I have used alubutyl in my Audi. Exactly as you say - on any large surface which can conduct noise by oscillating itself - doors, trunk, even the fuel tank, under the rear seat, etc.
I have used additional acoustic foam where space allows it.

My main goal was improving sound from the audio system and the improvement was appreciable even before I even touched any of the audio components. Sound-proofing should be the first step or at least a mandatory step in combination with audio upgrades. (My Audi (in reality Alpine) audio upgrade system came with a few sheets of Alubutyl as well!)

A small plastic cover which is supposed to reduce road noise is….. SciFi in my opinion….

I still intend to buy it and install it though…. Why get water and dirt through the hole if it can be covered.

[Jvac]

Originally Posted by Billfitz

Tire noise is primarily conducted through the air, because rubber is a natural acoustical insulator. Run Flats conduct more noise through the tire itself because of the extra sidewall material that's also stiffer than regular sidewalls.
Combating noise can be done two ways. One is to cover the sheet metal with vinyl mastic. I use this myself: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I haven't bothered to take out all the carpet and liner and put it on the sheet metal underneath, but if you want the car as quiet as possible that would be the first step. I have put it on any sheet metal that I exposed in the course of doing other work, like in my doors when I had the liners off to install true crossovers between the midranges and tweeters. Noise doesn't go through sheet metal, but rather the sheet metal vibrating is a source of noise. Adding mass with vinyl mastic reduces the vibration and therefore noise levels go down.
The next line of defense is to absorb noise once it's in the cabin. That's where heavy felt carpet underlayment comes in. The liner in my F34 is a full half inch thick.

Originally Posted by Skyhigh

Fully agree. I have used alubutyl in my Audi. Exactly as you say - on any large surface which can conduct noise by oscillating itself - doors, trunk, even the fuel tank, under the rear seat, etc.
I have used additional acoustic foam where space allows it.

My main goal was improving sound from the audio system and the improvement was appreciable even before I even touched any of the audio components. Sound-proofing should be the first step or at least a mandatory step in combination with audio upgrades. (My Audi (in reality Alpine) audio upgrade system came with a few sheets of Alubutyl as well!)

A small plastic cover which is supposed to reduce road noise is….. SciFi in my opinion….

I still intend to buy it and install it though…. Why get water and dirt through the hole if it can be covered.

That's good information fellas, thanks. I ditched the run flat tires long ago, and that was an improvement. My main goal is to enjoy the sound system so this sounds like the right approach.

[howe9191]

Just to share couple of my DIYs to solve the road noise. The one I feel a lil bit significant reduction (probably just 5-10% reduction)is the rubber seal across the door.

[auburnf30x]

Originally Posted by howe9191

Just to share couple of my DIYs to solve the road noise. The one I feel a lil bit significant reduction (probably just 5-10% reduction)is the rubber seal across the door.

I'll have to look into that rubber door seal. For the first time since I bought it (I think), I turned the radio off on the highway just to listen for where noise was coming from. Most of what I heard was from the run flats, but I did notice some wind noise slipping in around the front doors somewhere. Probably there.

[Skyhigh]

I installed the expensive piece of plastic yesterday. I did it for the sake of it and to prevent dirt from going in. I don't believe in any acoustic advantages.
I cleaned the area first and then applied a conservation wax around the edges:



I also ordered the clip, as per catalogue, just because the extra cost was negligible. However - not only is it unnecessary, as the OP stated already (the plastic cover fits securely), but I actually couldn't figure out where and how it is supposed to be used!? It does not fit anywhere Now I have a spare one

[bitcore]

Originally Posted by Skyhigh

I also ordered the clip, as per catalogue, just because the extra cost was negligible. However - not only is it unnecessary, as the OP stated already (the plastic cover fits securely), but I actually couldn't figure out where and how it is supposed to be used!? It does not fit anywhere Now I have a spare one

The part number 51757163899 looks like the clip/latch for a cover flap on the under tray which hides the oil drain plug on an E82.

[kingmonkey8]

I was always getting a feeling that my passenger side window wasn't sealing properly. It felt like I was getting more noise from the passenger window. It was subtle but my ear was always subconsciously getting drawn to the passenger side.
More noticeable on rough roads or when road noise is reflected back on the passenger side.
I checked the seals and tried pulling the door seal and re-attaching. I couldn't see anything obvious but it was still annoying me for a long time.
I had another look at the door seal but this time pulled it out completely and aligned as far into the top corner.
It has finally solved the issue. The car is quieter and the ambience feels balanced now.

[blckm328]

Thanks! It helped solving the problem!

[Alpinadrachten]

Originally Posted by kingmonkey8

I was always getting a feeling that my passenger side window wasn't sealing properly. It felt like I was getting more noise from the passenger window. It was subtle but my ear was always subconsciously getting drawn to the passenger side.
More noticeable on rough roads or when road noise is reflected back on the passenger side.
I checked the seals and tried pulling the door seal and re-attaching. I couldn't see anything obvious but it was still annoying me for a long time.
I had another look at the door seal but this time pulled it out completely and aligned as far into the top corner.
It has finally solved the issue. The car is quieter and the ambience feels balanced now.

What seal did you pull?

[Alpinadrachten]

Originally Posted by Skyhigh

I installed the expensive piece of plastic yesterday. I did it for the sake of it and to prevent dirt from going in. I don't believe in any acoustic advantages.
I cleaned the area first and then applied a conservation wax around the edges:



I also ordered the clip, as per catalogue, just because the extra cost was negligible. However - not only is it unnecessary, as the OP stated already (the plastic cover fits securely), but I actually couldn't figure out where and how it is supposed to be used!? It does not fit anywhere Now I have a spare one

And did it help?

[Skyhigh]

Against road noise? Of course not
Against dirt - I am sure it does.