[chicagoshark]

I feel like the 340 is loud, but still so much quieter then the Infiniti Q50 I was driving. So relatively speaking, it's an upgrade for me, but overall still "too" loud, but right now, it's not bothering me much. I assume it will in a few weeks...

Wonder how quiet the S4 is comparable to the A4. A4 is quiet, as is A6, but different class

[bluemark]

Originally Posted by chicagoshark

I feel like the 340 is loud, but still so much quieter then the Infiniti Q50 I was driving. So relatively speaking, it's an upgrade for me, but overall still "too" loud, but right now, it's not bothering me much. I assume it will in a few weeks...

Wonder how quiet the S4 is comparable to the A4. A4 is quiet, as is A6, but different class

Don't know about the S4, but I had an S5 out last week and I found it to be a quiet car. You do get a nice engine note, but no wind noise and road noise was minimal.

[instalher]

here is my road noise fix this gap is now sealed its on there with contact cement, ... my db reading is 76db at 100km per hr..

[bluemark]

Originally Posted by instalher

here is my road noise fix this gap is now sealed its on there with contact cement, ... my db reading is 76db at 100km per hr..

What is that picture of?

[EvenKeel]

Originally Posted by bluemark

What is that picture of?

Looks like an inner fender well.

[instalher]

pulled tire, removed plastic shield, and installed soundproofing, placed product on gap, all openings, all holes, works excellent.. little bit of work, but worth it.. tomorrow I due the back tire wells.. lots of rear road noise getting to the inside of the cabin...

[Shanta]

(My first post in this forum, but have been following this for quite a long time)

I have noticed that the F34 (3 Series GT) has additional front fender sealing.

Part Numbers: 51767377913 and 51767377914

Got them ordered from Sytner Leicester for 29 including plastic rivets for my wife's 330dx (63Plate acquired in Oct 17).

Drilled holes in my fender top side and fixed them. The sealing is complete albeit a bit wide, considering that the F34 fenders are a bit higher than the F30.

The car feels a lot more quieter (almost like my old e39 petrol, but not like my new G30 530d). Could not find anyone doing this on the net so thought of sharing this wisdom.

Other Improvements done:
Allround additional door seals (door bottom - used P type; door opening sides - used D-type)
Engine bay - used trunk seals over the chassis edge where the coolant container is fixed
Changed to Non-runflats - all 4 to Goodyear Eagle on 17" rims.

If anyone else has done anything similar please share.

[Billfitz]

I can't say if it's due to that sealing but my F34 is the quietest car I've ever owned, even with RFTs.

[bimmer456]

Can you record it and post on YouTube so we can hear what it sounds like?

[akgambino]

Originally Posted by Shanta

(My first post in this forum, but have been following this for quite a long time)

I have noticed that the F34 (3 Series GT) has additional front fender sealing.

Part Numbers: 51767377913 and 51767377914

Got them ordered from Sytner Leicester for 29 including plastic rivets for my wife's 330dx (63Plate acquired in Oct 17).

Drilled holes in my fender top side and fixed them. The sealing is complete albeit a bit wide, considering that the F34 fenders are a bit higher than the F30.

The car feels a lot more quieter (almost like my old e39 petrol, but not like my new G30 530d). Could not find anyone doing this on the net so thought of sharing this wisdom.

Other Improvements done:
Allround additional door seals (door bottom - used P type; door opening sides - used D-type)
Engine bay - used trunk seals over the chassis edge where the coolant container is fixed
Changed to Non-runflats - all 4 to Goodyear Eagle on 17" rims.

If anyone else has done anything similar please share.

Can you share some pics of these items you installed? Would be interested in trying to tackle this project

[akgambino]

Originally Posted by instalher

pulled tire, removed plastic shield, and installed soundproofing, placed product on gap, all openings, all holes, works excellent.. little bit of work, but worth it.. tomorrow I due the back tire wells.. lots of rear road noise getting to the inside of the cabin...

Can you take some pics of the rear install and post a diy when u do it? Sounds like your project might be easier to do than installing additional seals

[Shanta]

ok, today i measured the db with an app, and the readings were between 84 to 86 inside the car at idling. Probably a placebo effect, but i could swear it reduced the diesel clatter and sounded much more decent than before.

Nevertheless, here are the pics of the engine bay fender seals on my 330 diesel


Billfitz I see you do drive a petrol (Gasoline) engine, and i would tend to agree that those engines are by far the quietest unlike my 6-pot diesel

[JimBean2014]

Originally Posted by chicagoshark

I feel like the 340 is loud, but still so much quieter then the Infiniti Q50 I was driving. So relatively speaking, it's an upgrade for me, but overall still "too" loud, but right now, it's not bothering me much. I assume it will in a few weeks...

Wonder how quiet the S4 is comparable to the A4. A4 is quiet, as is A6, but different class

I switched from S4 ( had it for 3 yrs) to 340 w/mppsk no RFTs..340 is noticeably noisier in terms of wind/road noise ..

[anh3]

340i-my driver side window was making whistling noises, most noticeable when sunroof is cracked/vented. So I figured I need to to something about it, by adjusting all four latches. No more noises, seems quieter. Just have to give the doors more effort when closing them, louder thud!

[Thethinkingbear]

The noise is caused by the run-flat tires

[MEN54]

Originally Posted by CKau

I know what you mean. As I've written earlier, the problem with getting noises fixed is that it unmasks the remaining residual noise sources that remain.

It bugged me that I've come so close, yet remain so far. It's only on certain rough surfaces that I still hear some kind of sound vibration permeating into the cabin... kinda like the aircraft fuselage noise. When the road surface changes to something smooth, that noise goes.

Now that the other noise sources have been removed, it's annoying how it's there. I'm not sure if it's the same noise as yours, but here goes (and I know your door adjustment did nothing).


As a very simple experiment, I leaned forward in my seat on the rough road surfaces and noticed that I didn't hear the tyre roar like I did when I sat back into my backrest.

Even though my doors have been adjusted it lead me to believe that tyre roar is still somehow getting into the cabin.

I recalled being disappointed at how large the panel gaps are in BMW's. Even the Korean & Japanese cars don't have large gaps like we do. I cringe when I re-watch the F30 being manufactured and seeing how big a gap the foreman accepts when he uses his spacing tool.

So I theorised that the gap between the bottom part of the doors, being larger than on most other cars, must be responsible for it. I think the door cavity is channeling the tyre roar up the bloody b-pillar!

When I took the following measures, I was proven right!

Here's some pics of what I did....

First I upgraded my car to the standard of most other 21st century cars... I placed some "d" profile sound proofing rubber to the join between the front and rear doors


I placed the seal on the front edge of the rear door with the "d" facing rearward.



Did the same on the rear edge of the front door (which overlaps the front edge of rear door) this time with the "d" facing forward i.e. the opposite direction (see blue arrow).



I purchased some foam and placed two layers on the bottom edge of the front door. I placed it so that the flat machined edge is flush with the bottom edge of the door. Note the first layer does not block the drains in the door.



When you shut the door, the foam doesn't protrude out, but you can see it does fill that whopping big 2-3mm gap that BMW left along the bottom edge of the door.

I then stuck another layer on top of the first to fill as much of the cavity as possible where the bottom edge shuts. You will see what I mean... if you open the front door and inspect the bottom edge of the rear door you will see how much of a gap there is between door & chassis, as well as bottom edge of door & sill.


I think the foam along the bottom edge contributed the bulk of the sound reduction.

Rather than get lazy, I also sealed the rear door with rubber seal along the side edge



Likewise inserted two layers of foam along the bottom edge of the rear doors.



To ensure I was absolutely happy, I put some foam along the upper side of the front door just behind where the plastic strip will touch the rubber of the front edge of the rear door. I also cut an old bicycle tyre tube & taped it to ensure a tight seal.



Frogman, hope this helps you. Hopefully it will & you can enjoy the quiet.

After road testing my latest mod, I honestly think I'm done now :-)

Where did you get that foam pad you put next to rain drain hole?

[ndshgyta]

Originally Posted by Frogman

The following chronicles my sound reduction activities today.

Summary: To my totally uncalibrated, old, dirty, and hearing-loss ears, all of these changes seemed to deaden the road and wind noise significantly. I think what I hear now is the actual window noise caused by mirror turbulence. I guess the only way to confirm that is to remove the mirrors and see if the buffeting noise goes away. Humm, how to convince the SA to write that up!! That, or I'll just turn up the death-metal a few more clicks and stop worrying about it!


CKau, I also noticed that the back of my front doors stick out about 2mm from the front of the back doors and the back of the back doors stick out about 1mm from the rear frame. I'll ask BMW to adjust the door the next time I take it in.

Part 1: The Strut Area.

My previous strut fix (documented above) helped a little , but not very much. Plus, I didn't like the idea of unprotected foam on the right side against the exhaust heat shield.

Then I saw CKau's new work and decided to try again.

I was out running errands and swung by my local foam store. They only carry foam products.

I noticed that they had a roll of Ensolite Acoustical Firewall foam which looked perfect for the wheel lining area. It is 1/4 inch dense foam (maybe neoprene) with a metal foil backing. I got a foot of it (1 foot by 3 feet).
I also picked up some 2 inch acoustic foam; they had a lots and lots of it.



So, I first re-did the strut holes. I used a bit of the firewall foam to be on the inside of the chassis (metal foil facing inside the engine compartment) and kept it in place with some of the 2" foam cut down to 1".



Installation was easy.

Firewall foam first, then 2" foam to hold it in place (taken from the left wheel well):



View from the engine compartment, left Side:



Right side:




Part 2: The Fender Gaps.

Next, I filled the upper fender gaps with most of the 2" foam (about 4" by 14" on each side). You could store a gallon of water in there! Again, installation was easy, I just stuffed the foam in there.

Right Side, Left Side:



Part 3: The Plastic Wheel Covers.

Next, I covered the wheel well plastic. Man, that is thin stuff! I just tucked the firewall foam between the plastic and the metal which shaped the foam perfectly and the wires kept everything in place.
I did need to use a little bit of outdoor mounting tape to hold down the front end of the foam at the bottom.

Right side, before and after:



Left Side, before and after (there isn't as much room here to add the foam because of the radiator reservoir and A/C pipes)




Part 4: The Door frame Gap.

Lastly, I filled the door gaps with 1/2" backer rod and some left over 2" foam for the big open square at the bottom of each door.



I tried covering the vertical gap with tape (I even used red electrical tape), but I just couldn't get my hands into the area to lay the tape down effectively.

CKau, how did you get tape in there??


Left side, before and after (lower):





Final Summary:

I'm done playing with foam! This car is meant for driving, not arts and crafts.

This was about 2 hours of fun cutting foam and stuffing it into nooks and crannies.

I can't tell you if it was worth it for you or not, but it was for me, so I'm happy!

Thanks again KCau for the hard work, and ingenuity in figuring this out.

please reu0load pictures because we cant see it !

[Billfitz]

Originally Posted by Thethinkingbear

The noise is caused by the run-flat tires

My BMW with Conti RFTs is quieter than my Altima with Michelin Primacy MXV4. That doesn't mean that a non RFT might not be quieter on my BMW, but there are many more sources of noise than just the tires.

[ndshgyta]

Frogman please reupload the pictures!

[agentorange]

RFTs are huge contributors to noise in modern cars. Just bought my wife a GLC and that thing is vault quiet except for tire noise.

Now, you want REAL road noise, try the 2020 Hyundai Aceent rental I just had while away on business. Not only was it road noisy, it had the noisiest windshield wiper system I've ever heard on a post 2000 car. Somebody got cheap leaving out the rubber isolating mounts, I suppose.

[alex1991]

So I can see that f30 has the same problem as my X1 (2011).
So I have to put:
The insulation hood cover,
I have sealed all door (I have put the sound deadening self-adhesive pads on the door metal all 4)
I have put extra door seals on all doors, hood, and trunk

And this reduced noise for 10dB, measuring before and after on the same phone and same conditions.

My next project is:
To close the gap between doors and fenders well
To remove wheel well plastic cover and put the same self-adhesive pads on them and then put them back (all 4)
To close long gaps in the hood

My whole next project will be almost everything that I have seen on this forum.
A lot of informations, thank you a lot.
I will do dB measurements and I will post them here

[DL335D]

Originally Posted by kadify

I have those on my 4GC as well. The 4 isn't quiet by any stretch of the mind.

100%. I have a '16 435GC and a '17 f80 with 20" wheels. Both on PS4S. The 435GC is definitely louder.