UK-POLOS.NET - THE VW Polo Forum

Well as I relayout'ed my boot for my amp today and I have decided to figure out where the rattling sound comes from when I turn the volume up and with lots of bass pumping from my sub.

Volume 18 all doors/boot shut and yes I can hear lots of annoying and VERY loud rattling noise coming underneath the car at the back.

Do you guys get the same thing? Talking about 9N here.

Right, so I went on the floor and with my "flash light" I looked everywhere, first I thought it came from the heatshield around the exhaust box, but no it wasn't. Further looking inside the bumper I saw a purple thing flapping.

Looked inside the boot and this is what I found.



So I looked and I saw that purple "thing" again, but from the inside. So with the effort I managed to unclip that bastard, which I know was one of the reason why it was flapping/rattling.




"Thing" removed, leaving hole behind.





Know what I mean guys? It appears to be some form of venting thing, which has a plastic cover on it and can be easily opened.

What the hell is it doing there and it makes a very loud flapping noise when my bass is turned up. Dunno if you guys have the same issue here.


Next I also realised that the rear bumper caused a lot of "distortion" sounds too when the bass is pumping along with the number plate. What should I do? Stick some Dynamat inside the bumper or something? At first I thought it was the spare wheel bit that made the rattling noise, but it appears to be more of an outside issue.

Sorry if I went on a bit here, but I wanna give detail about the situation and another apology to the quality of the images, been taken in a dark area (garage) and from my Nokia 6230 camera phone.

Thanks for your time and help.

Time for bitumen

I did my hole car with that stuff to prevent the audio make the car rattle.

It changes the structure of the material you put it on. When ticking with my hand on the floor of the boot it makes a beeeengg booooiiing noice.

With the bitumen it's bong bong bong.

The airvent works like this:

The fresh air is coming from the front vents. Air travels through the car and via these vents in the back the flow gets out of the car. So the air can be nicely refreshed.

Look at your last picture. The black stuff under the plastic vent is bitumen. Unfortunately VW just covered a small piece of the boot.

After the bitumen I also worked with some noice-reducing stuff.

Thanks for the help.

Interesting stuff, but what exactly is that Bitumen stuff and where can I get hold of it?

And what about the rattling noise given off by the bumper? I swear it is that 'cos I put my hand on it and it greatly reduced the distortion noise (the rear bumper I mean).

bitumen is just dynamat, its the black sticky crap on the back of the foil

Oh right. 'could of said that in the first place

You using that stuff then?

tim wrote:bitumen is just dynamat, its the black sticky crap on the back of the foil

Ah right, that was the word I was looking for.

I've done my hole boot, the metal under the backseats, and the metal behind the kickpanels in the back.

aha. What is the "kickpanel"?