Sound deadening

Bosanek wrote: I am planning to sound proof my Jimny by installing sound insulating / deadening and absorbing materials.

I have a few questions at the moment.


When I removed the carpet from the cabin floor, I noticed three things:

1.
Most of the front floor surface (from below the dash board to the step in front of the rear seats) is factory coated with bare bituminous material. I do not know if earlier Jimnys have this much bitumenous sound deadening coating on the floor. Mine was made in 2012 for the German market.

2.
About 66% of the carpet surface is covered from below with 15 mm thick "cotton-like scrap" material. It appears that everyone names it differently. Some of the names: felt, fleece, cotton dew ...

3.
A significant part of this "felt" material was slightly wet upon touch, and that correlates with significant rust blisters in the floor wherever some seam or panel joint is (although the vehicle is only 7 years old and has never left tarmac).
A contributing factor to this wetness of the material is probably that the vehicle has always been driven with carpet front floor mats, instead of rubber floor mats ...


My questions are:

1.
Since this bare bituminous material is obviously el-cheapo factory work just to get some deadening done, would it be recommended to remove it all and install proper high-quality alubutyl sound deadening sheets instead? Does anyone know if this factory material is bitumen at all or something else in fact?
Butyl generally is a much better vibration deadening material than bitumen, and the aluminium foil on top of it improves its performance further more.
However, I am worried if it would be possible to properly "imbue" the alubutyl panels to the uneven front section of the vehicle floor. Has anyone done it?
Also, how difficult is it to remove this factory bitumen coating from the floor?


2.
Has anyone else experienced moisture / rust accumulation issues under the carpet with this factory cotton scrap felt?
Would it make sense to remove all this cotton scrap felt from the carpet and install proper waterproof (closed cell) sound proofing foam below the carpet?
How thick could it be before I run into problems with fitting the carpet back into place? Since the current cotton scrap felt is 15 mm thick, I was thinking that 20 mm should still be OK. What about something even thicker?

Cant answer all youre questuons, but in my 2006 , ive used sound deadning bitumen mats (from a car stereo shop) on the entire floor from front seats and back to the rear door, on inside of both front doors, rear side panels, and alittlebit in the rear door.

A very big difference from stock noise levels. Especially rear side panels and rear floor/wheel wells did most of the change..
Car feels more solid, and you dont get all the noise from sand/rocks in the wheel wells that makes the stock jimny sound like a tin can.

I did look at the options for doing similar and eventually decided that really a Jimny on road tyres isn't sufficiently loud to warrant the expense and effort. It's never going to be rolls Royce quiet unless you add that much sound deadening that it can hardly move under the weight of it. Besides the little clicks bangs and buzzes add character.

OlaGB,
when you stripped your car's interior to add the vibration deadening bitumen sheets, did you encounter significant floor surface coverage with existing factory bitumen coating on the floor below the front seats and below the rear seat bench?

If you did, what did you do with it?
Did you remove it and then apply your own coating, or just left it like that and applied the coating just to non-factory covered areas, or applied your coating on top of the factory coating?

Also, after you were done, were all the interior body panels close to 100% percent covered with sound deadening plates or were the significant areas (which) that you did not cover?

Bosanek wrote: OlaGB,
when you stripped your car's interior to add the vibration deadening bitumen sheets, did you encounter significant floor surface coverage with existing factory bitumen coating on the floor below the front seats and below the rear seat bench?

If you did, what did you do with it?
Did you remove it and then apply your own coating, or just left it like that and applied the coating just to non-factory covered areas, or applied your coating on top of the factory coating?

Also, after you were done, were all the interior body panels close to 100% percent covered with sound deadening plates or were the significant areas (which) that you did not cover?

Where there was stock bitumen mats, i just put mine on top of them.

The entire floor from backdoor is covered, all the way down to the floor in front of the rear seat. The rear wheel wells are also covered, and they are important to get rid of the noise from sand and rocks from the wheels.
On the outer plate of doors and outmost rear sidepanels, i didnt cover100%, but as much as i could reach basicly..

Could have done alot more, but i didnt see the point of adding loads of weight for another few percent more silencing.
I believe i have covered the panels that really matters. Just knock on the panels before/after, and you will know what i mean

Don't forget the roof

Keithy wrote:

Don't forget the roof

Soo tempting when i was at it, but didnt want to mess up the roof liner.. Read several places that its a biatch to remove/install!