[VegasG42]

Are those connected to anything ? As in connected to the HVAC system ?

Or are they just open vents to basically connect the truck to the cabin for some type of airflow ?

You can't really see them just by looking at your rear deck lid, but if you put your hand where the rear window meets the rear deck lid, you will feel the vents, that I am assuming just go to the trunk.

The reason I am asking is because I have a crazy amount of rattle coming from the desk lid after installing a subwoofer in the truck.

I lifted up on the deck lid a bit by using the vent holes as a hand-hold, to which this alleviated much of the rattle.

So I'm wondering if I could cram some sound deadening material , or some other foam or something into maybe on of the vent holes to push against the deck lid to stop the rattle.

I REALLY don't want to disassemble the entire rear to actually add sound deadening material.

[Pentland]

Not quite sure what vents you are talking about (a photo would help) but they could be there to stop the pressure when shutting the boot lid blowing out the rear parcel shelf.

[VegasG42]

Originally Posted by Pentland

Not quite sure what vents you are talking about (a photo would help) but they could be there to stop the pressure when shutting the boot lid blowing out the rear parcel shelf.

Vents perhaps wasn't the best term.

It actually looks to be one large opening that runs about 60% of the length of the very bottom of the rear window / rear deck lid.

[Pentland]

No idea. On EU cars the rear window is heavily tinted. You can hardly see the heating elements let alone that gap. Only know it there if you reach in from the inside as you said. It’s not accessible from the boot.
Not much help sorry.

[Navin_Johnson]

Originally Posted by VegasG42

The reason I am asking is because I have a crazy amount of rattle coming from the desk lid after installing a subwoofer in the truck.

I've pulled up to a stoplight and felt the bass coming from the car stopped next to me, and I swear I heard my car starting to rattle too. Granted, the car I was in was 15 years old and had a lot of rattles of it's own by then, but still, does the bass have to set so low that it not only can be heard, but felt in nearby cars?

There is another thread here from a user with the same problem and he pulled the back seat and rear deck out of the car to fix it. Look it up to see how much success he had with the project.

[VegasG42]

Originally Posted by Navin_Johnson

I've pulled up to a stoplight and felt the bass coming from the car stopped next to me, and I swear I heard my car starting to rattle too. Granted, the car I was in was 15 years old and had a lot of rattles of it's own by then, but still, does the bass have to set so low that it not only can be heard, but felt in nearby cars?

There is another thread here from a user with the same problem and he pulled the back seat and rear deck out of the car to fix it. Look it up to see how much success he had with the project.

I suppose it is the nature of having an amplified 12 inch subwoofer in the trunk. I've owned the set-up for several years , so naturally I installed it into this vehicle as well. Otherwise, I probably would have went with something a bit more mild, such as a smaller 10 inch sub.

And even with this subwoofer, I had planned to keep the settings fairly low. However , the rear deck lid rattles so easily that I found myself turning the settings up to drown out the rattle.

Believe me , I understand how ridiculous it looks when you pull up next to a car and they are bumping their stereo and everything is vibrating like crazy . That's one of the reasons why at stoplights I lower the volume , lol.

I will have to find the thread you mentioned. But I really want to avoid taking apart the entire rear of the car. That's why I'm trying to find out if it is safe to jam a bunch of material into that vent to push up against the deck lid to stop the rattle.

[Navin_Johnson]

This is the thread I was referring to:

https://g87.bimmerpost.com/forums/sh....php?t=2065966

The poster's rattle wasn't caused by a sub, but someone else replying to the thread did mention music/ subs was causing a rattle. That's what I remember reading.

[VegasG42]

Originally Posted by Navin_Johnson

This is the thread I was referring to:

https://g87.bimmerpost.com/forums/sh....php?t=2065966

The poster's rattle wasn't caused by a sub, but someone else replying to the thread did mention music/ subs was causing a rattle. That's what I remember reading.

Yeah , that looks like a way to kill an entire weekend

[TJZ67201]

Those “vents” you are referring to vent air from the trunk to the cabin. They allow for pressure equalization when closing the trunk. They are not connected to any HVAC

[VegasG42]

Originally Posted by TJZ67201

Those “vents” you are referring to vent air from the trunk to the cabin. They allow for pressure equalization when closing the trunk. They are not connected to any HVAC

So it's literally just an opening that essentially connects the cabin of the car to the trunk?

Do you think there would be any harm into inserting some type of material , just enough to push up and put pressure on the deck lid?

[TJZ67201]

Originally Posted by VegasG42

So it's literally just an opening that essentially connects the cabin of the car to the trunk?

Do you think there would be any harm into inserting some type of material , just enough to push up and put pressure on the deck lid?

Before installing sound deadening per my thread that was linked earlier, I used foam pool noodles to push up on the plastic in the cavity underneath the deck lid. This fixed a rattle I had with very loud bass.

There are 2 large enough holes in the roof of the trunk to get your hands up there and wedge something. You’ll just have to feel around or reference the photo I’ll attach

[VegasG42]

Originally Posted by TJZ67201

Before installing sound deadening per my thread that was linked earlier, I used foam pool noodles to push up on the plastic in the cavity underneath the deck lid. This fixed a rattle I had with very loud bass.

There are 2 large enough holes in the roof of the trunk to get your hands up there and wedge something. You’ll just have to feel around or reference the photo I’ll attach

Pool noodles - that's brilliant. Very cheap , very lightweight , and the material is perfect.

If I can jam pool noodles under the deck lid, this might really help with my rattle issue.

[TJZ67201]

Originally Posted by VegasG42

Pool noodles - that's brilliant. Very cheap , very lightweight , and the material is perfect.

If I can jam pool noodles under the deck lid, this might really help with my rattle issue.

Yes! One will do if you cut it up. It worked great for me until I removed the whole rear parcel shelf.

Apparently that vent rattle has been present on BMWs for many years

[VegasG42]

Originally Posted by TJZ67201

Yes! One will do if you cut it up. It worked great for me until I removed the whole rear parcel shelf.

Apparently that vent rattle has been present on BMWs for many years

When I crawled into the backseat, reached my hand back there and tugged on it, I was surprised how much the whole parcel shelf moved up and down when I pulled on it. I even pressed down on it thinking maybe some of the fastener clips weren't properly seated.

But nope, the vent and everything else is kind of just sitting there lol

[RockCrusher]

Originally Posted by VegasG42

Are those connected to anything ? As in connected to the HVAC system ?

Or are they just open vents to basically connect the truck to the cabin for some type of airflow ?

You can't really see them just by looking at your rear deck lid, but if you put your hand where the rear window meets the rear deck lid, you will feel the vents, that I am assuming just go to the trunk.

The reason I am asking is because I have a crazy amount of rattle coming from the desk lid after installing a subwoofer in the truck.

I lifted up on the deck lid a bit by using the vent holes as a hand-hold, to which this alleviated much of the rattle.

So I'm wondering if I could cram some sound deadening material , or some other foam or something into maybe on of the vent holes to push against the deck lid to stop the rattle.

I REALLY don't want to disassemble the entire rear to actually add sound deadening material.

The venting could be there to allow cabin air to flow through and into the trunk and on to the outside of the car.

I've not seen these on my BMWs but with other cars -- see attached pic of my Boxster's rear -- there are rubber flaps located in the sheet metal that is hidden by the rear bumper cover. These rubber flaps are normally closed. But will open from just a bit of air pressure behind them and because they are located in a low pressure air allow air flow from the cabin.

The pic is not very good but you can just make out the rubber vent I am talking about It is located inside that rubber duct.

I would not block the venting but you could certainly judiciously apply thin strips of felt to eliminate rattle.

[Pentland]

Originally Posted by RockCrusher

The venting could be there to allow cabin air to flow through and into the trunk and on to the outside of the car.

Unlikely. If you look at the boot lid, there is a rubber seal all around it.
The gap is there as I said in post 2 is to allow air to move so you can actually shut the boot and doors without popping something like the parcel shelf or worse, the windows.