[sylonien]

So.... finally managed to install my subwoofer in my E92 M3 with HiFi audio.
But unfortunately immediately there is massive vibration / rattle from the rear parcel shelf.

I can see it bouncing up and down from the mega bass.
I looked underneath and there seem to be a small gap hole between the parcel shelf and the boot area.
I guess that's blasting the sound through that bit
and causing it to rattle like mad.

Not sure how to fix it. I tried stuffing that hole with foam but its rattling.
Next step is to try and remove the shelf and dynamat it like mad?

[alexwhittemore]

I've got the same problem, even worse since my setup is IB. As it stands, I've stuffed some exercise mat (leftover from making a gasket for the IB install) up into the holes you mentioned. The problem is, there's a HUGE gap between the top of the trunk (sheet steel) and the actual shelf (light fiberboard, or whatever it is). One of these days I'm planning to pull out the shelf and stuff in a couple of big blocks of open-cell foam, the kind you'd get to make furniture cushions. As far as dynamat goes, I think it's sort of a failing strategy - the parcel shelf itself is basically a big diaphragm, adding dynamat to it will mitigate the problem but it'll still be one big diaphragm into the car, and it'll still vibrate, and it'll still sound annoying.

[sylonien]

Exactly my problem and what I'm thinking.
I've stuffed some foam up that hole and made zero difference.
Took the ski hatch cover out and the armrest as well, still no difference.

However! I climbed to the back and listened around I actually found out the

'05 COVERING HEADLINING REAR ANTHRAZIT 1 51447960075'

is making most of the buzzing vibration sound!! I pressed my palm on it and most of it is gone.

Gonna try and figure out how to take that of and dynamat / foam the hell out of it.

But still, will tackle the shelf still cause like you said, I can see it bouncing around like a diaphragm.

[kaigoss69]

Originally Posted by sylonien

Exactly my problem and what I'm thinking.
I've stuffed some foam up that hole and made zero difference.
Took the ski hatch cover out and the armrest as well, still no difference.

However! I climbed to the back and listened around I actually found out the

'05 COVERING HEADLINING REAR ANTHRAZIT 1 51447960075'

is making most of the buzzing vibration sound!! I pressed my palm on it and most of it is gone.

Gonna try and figure out how to take that of and dynamat / foam the hell out of it.

But still, will tackle the shelf still cause like you said, I can see it bouncing around like a diaphragm.

Is that the cover for the brake light? Mine was rattling too and I put some Dynamat between it and the glass, and it took care of the problem. Only problem is, the Dynamat smeared a bit and is now visible, if you look really hard.

[sylonien]

Yup, I just cut some foam in the shape of that brake light cover and pushed it back on.
And it stopped most of the rattling now coming from the rear.

Still a little around the back in general and quite a lot from the outside near the rear. I suspect its the heat shields around the exhaust. But not much can be done about that?

[Quasimodem]

I am running into a problem with a third brake light rattle. It is not really a "rattle" but the same sound you get if a piece of paper or receipt makes its way onto your underseat subs.

The sound is not from the cover in the middle of the rear of the headliner. I removed that cover completely and the vibration is still there.

Here is a DIY link if anybody is removing that cover or the brake light:

http://www.e90post.com/forums/showth...ight=headliner

So I removed my brake light (following these instructions). By the way, you dont have to remove the cover in front of the brake light in the headliner entirely, just rotate it down to access the sliders to remove the rear brake light.

I first tried putting green felt dots on the top of the brake light figuring that it was vibrating against the window. That didnt work.

Then I removed the white bracket holding the powwer connector. That didnt work.

Now I am thinking it might be the sliders themselves. This is going to be a problem since it would be some kind of internal vibration on either the light housing or the anchors which are glued to the rear window. I am going to try wrapping different surfaces of the sliders or the plastic pieces they hold together to see if that will tighten them up and stop the rattles.

Does anybody have any experience sound deadenning the third brake light housing?

Edit: Now after looking at the housing more closely, I think the noise might be coming from the location the power wires go through the LED PC board. There are little gaps in the PC board which the wires go through and they seem to rattle around in those gaps. Since that will be easier to deaden than the sliders, I am going to work there first. I am probably going to pull the wires out of the connector and put some electrical heat shrink tubing on the wires to thicken them where they go through the PC board. I will let you know if this works.

[sylonien]

Hello buddy,

At first I thought it was the parcel shelf, which it did make a little rattle.
But later I found that it was the 3rd brake light area that was flapping like mad.

So here's what i did and it cured 90% of the rattle and I haven't done any sound deadening or anything with the parcel shelf ever since and it was fine in my case.

You see the yellow arrows? Thats' what's causing the rattle in my case.

So I took the cover off (green arrow).

And simply cut a some foam in that shape (pink) and wedged the cover back on. Bit of a tight fit, but that's what stopped the rubber seal around the light flapping against the back window?

Solved the rubber flapping about (yellow arrow). Worked for me somehow.

Couldn't believe it worked and for nothing. Just found some foam in the house.
And piss easy. 10 minutes?

[Quasimodem]

Originally Posted by sylonien

Hello buddy,

At first I thought it was the parcel shelf, which it did make a little rattle.
But later I found that it was the 3rd brake light area that was flapping like mad.

So here's what i did and it cured 90% of the rattle and I haven't done any sound deadening or anything with the parcel shelf ever since and it was fine in my case.

You see the yellow arrows? Thats' what's causing the rattle in my case.

So I took the cover off (green arrow).

And simply cut a some foam in that shape (pink) and wedged the cover back on. Bit of a tight fit, but that's what stopped the rubber seal around the light flapping against the back window?

Solved the rubber flapping about (yellow arrow). Worked for me somehow.

Couldn't believe it worked and for nothing. Just found some foam in the house.
And piss easy. 10 minutes?

Good to see somebody else has the same problem. However, I am not convinced that the rubber seal is rattling. How can soft rubber rattle?

Nevertheless, you may have stumbled on a solution.

I have no doubt that the plastic and rubber area you point out is vibrating. Maybe that is "tweaking" the main light area (where the PC board is sandwiched between the red lens and the black plastic) to squeak or rattle. When you put foam on the rubber seal, I suspect you either released air pressure or placed more torque on the PC board area, thus reducing the rattle indirectly. Pushing the rubber away from the glass will also put some torque on sliders which hold the assembly to the studs glued to the glass, so your solution might solve a rattle within the sliders without having to apply tape or felt to those areas too.

I will certainly try this because the alternative is physically disassembling the whole thing, and putting it back together. This would be a problem because the red plastic lens is secured with melted plastic rivets. So to take it apart (to apply glue or felt to deaden the inside of the brake light PC board area) would require me to drill out the plastic rivet heads and leave me with the problem of reassembling it with those hard plastic rivet heads missing.

I was just about to use my dremel and cut through the top of the red plastic lens, remove the top four rivet heads and soundproof the PC Board inside the assembly. See yellow dotted line and arrows pointing to the rivet heads I would have to remove on the photo below. But this is a last resort, I will try your solution first. Thanks.

[sylonien]

That's because I climbed to the back with a track of Pendulum - Set Me On Fire blasting away and touched around to see if I could locate the rattling sound.

Eventually I found that rubber seal flapping away.

I tried holding my hand against the third brake light cover and it helped a bit
and I touched around the rubber seal (yellow arrow) and definitely was coming from there.

I could of sworn it was the parcel shelf at first.

Somehow the foam cured my rattle. Try it on yours and see if it helps?

[Quasimodem]

Originally Posted by sylonien

That's because I climbed to the back with a track of Pendulum - Set Me On Fire blasting away and touched around to see if I could locate the rattling sound.

Eventually I found that rubber seal flapping away.

I tried holding my hand against the third brake light cover and it helped a bit
and I touched around the rubber seal (yellow arrow) and definitely was coming from there.

I could of sworn it was the parcel shelf at first.

Somehow the foam cured my rattle. Try it on yours and see if it helps?

Well, moved those green dots of felt that you see in my pictures above to the inside edge of the rubber seal that you are talking about and it appears to have stopped the rattling sound. I dont quite understand it since I dont see how rubber can rattle.... Regardless, it seems to work and that was a big annoyance, thanks.

[sylonien]

I'm not sure either, but as long as it works