Noise from rear window

[bose213]

Hello.
I hear cabin noise from the back like there is no rear window. I suppose it’s coming from the holes above the window. What is their purpose? Should there be any foam rubber behind these holes or something to block the noise?
Thanks.

[Showdown]

There is supposed to be open cell foam in that cavity to allow airflow out from the. Anon but even with foam it’s a major source of noise.

I filled mine and it was a very noticeable reduction in the sound when driving at speed. Then again, I have pop-out rear vent windows that allow air to escape when open.

[porsche930dude]

You can also do the third brake light mod it blocks the vent pretty well https://forums.pelicanparts.com/porsche-911-technical-forum/1077624-theon-design-roof-vent-rear-brake-light.html

[Showdown]

That’s exactly what I did on my car and I think in that thread I explain how to do it without removing the window or headliner by fishing the wires in through the luggage hook hole. Wasn’t super easy but well worth it.

[bose213]

Got it. Thank you.

[PeteKz]

Duct tape.

I cover the vents when I know I'm doing a road trip, and in the winter. I'm sure there's a more elegant method, but this is quick and easy.

[GH85Carrera]

The vents are there for a reason. If the heaters or the AC blower are running at max, the air has to go somewhere. The factory put foam in there. From what I understand the only way to replace the old foam is the remove the headliner.

Not long ago I was driving west on I-40 with a legal speed limit of 75, but most cars moving at 80. There was a 50 MPH headwind, and my rear vents were howling. I had the heaters on, but only only on the first position of the blowers.

I thought about the third brake light LED options, and since it blocks the air flow, I did not order one. In the summer I run the AC and I want that air to move through the cabin to keep me cool.

[PeteKz]

I have enough other places where air gets in and out that I don't need to worry about blocking that vent.

From the last time I installed my new headliner, I'm pretty sure that you can just peel back the rear edge of the headliner and get access behind the vent to clean out deteriorated foam and install new. But that requires removing the rear window. If you have a sunroof, it may be possible to reach in there by unzipping the access seam.