Low frequency 'boom' in cabin

[renton]

Has the silentcoat made much of a difference to any roadnoise too ?

[mork23]

This one

 

http://www.ebay.co.uk/itm/Silent-Coat-Hatchback-Car-Boot-Sound-Proofing-Pack-2mm-Mat-Deadening-Insulation-/181614920735?hash=item2a4917c41f:g:pT0AAOSwCQNWcsfZ

 

I used a decorating seam roller to flatten it onto the surfaces.

Did you have any excess sheets from this?  I'm wondering whether there's any difference with including the isolator sheets as well as the regular silent coat.  I'm planning on doing under the back seats too but I'm guessing this pack isn't big enough alone.  Therefore, do I double up this purchase or just buy silent coat sheets in a large enough bundle without the isolator?  Feedback would be appreciated.  Thanks

[skd12]

Did you have any excess sheets from this? I'm wondering whether there's any difference with including the isolator sheets as well as the regular silent coat. I'm planning on doing under the back seats too but I'm guessing this pack isn't big enough alone. Therefore, do I double up this purchase or just buy silent coat sheets in a large enough bundle without the isolator? Feedback would be appreciated. Thanks

I had a small amount of the foam and maybe for or five sheets of the heavy silver dampening stuff left.

You don't need 100% coverage with the dampening for it to make a difference. I think the foam is best to cover as much as possible though.

I've not ventured under the back seat but I reckon there's enough left to do the job.

I've not factored the foam into that add I don't think it would fit.

I'm going to attempt the front doors too at some point.

[mork23]

Great, thanks for that!

[skd12]

Has the silentcoat made much of a difference to any roadnoise too ?

I'd say it's reduced it by a noticeable amount. I've got a diesel vrs on the 19" Xtremes and it's noisy but this has made it better. I'd like to do the front footwells/firewall but don't fancy messing around removing carpets and trim in case they don't go back right.

 

I did under the rear seats this afternoon and took a couple of photos

 

Before:

 

Clips at the front of the seat base:

 

This bit gets stuck on that bit. You wrench it upwards but I managed to unhook it:

 

After:

[ExSEAT]

XDQ, Id be interested in doing under the seats, I have a bit of silentcoat left so I may as well. Could you give me a four or five step guide as to how the seat comes out please? Ive not tried it before!

 

Anyway, a quick recap....

 

I picked up my VRS TSI a few weeks ago and noticed the booming, especially over shellgrip on roundabouts pretty quickly. Its since been in for some boot adjustment and whilst the boot isnt extremely tight they did move the stops and the catch. That has made a small but noticeable improvement. Tonight I spent 30 mins fitting some 2mm silentcoat into the wheel well under my spacesaver. I havet went wild but basically the pan bit and a little up the side at the front most part of the well is covered, took around 8 sheets. A test drive with the blowers off and the radio turned down has again showed some improvement. Only on the roughest of road would I pick up the boom. I'm willing to do some more coating but it may only be sporadic.

 

At this point Im pretty happy, given that I got rid of my Leon FR because of rattles and road noise I find thats quite impressive. Its never going to be as quiet as a Rolls but its not at the point of annoying me anymore right now.

 

Having said that, I'm up for anything that can make it even better, a little more effort cant hurt. So what Im planning on top of the silentcoat under the seats (if I can man up and take the bench out) is fitting some slim 'egg box' type sound deflection foam onto the underside of the parcel shelf, to hopefully dissipate any sound waves eminating from the boot. Can't hurt! Any thoughts?

 

All the best

[skd12]

XDQ, Id be interested in doing under the seats, I have a bit of silentcoat left so I may as well. Could you give me a four or five step guide as to how the seat comes out please? Ive not tried it before!

 

 

Someone else has posted how to do it but here's a recap:

 

1) Remove the plastic covers from the isofix fixings x4 - they lift and pull out

2) Remove the plastic surrounds from the isofix fixings x4 - these take a bit of wiggling but come out quickly enough

3) There are two clips which hold the seat base in place. These are one on each side, near the front. An upwards tug will undo these.

4) There are two metal lugs which were caught on the foam. One at either side towards the back. You could just pull it up at the point and risk tearing the foam but I managed to squeeze the base backwards and over the metal on one side at a time.

5) Lift it out

 

Apparently you're supposed to replace the plastic retaining clips after removing the seat base but mine seem fine. I have been waiting for the warmer weather before doing these tasks so that the plastic clips are less likely to snap.

[ExSEAT]

Brilliant, thank You so much. I will look at that at the weekend! Worried about the clips a bit lol!

[skd12]

I think the worst that would happen would be that you'd introduce a new rattle until they were replaced.

 

Have a look at my post #897 I've done the entire surface under the boot floor lid thingumy. About 66% coverage with the silentcoat and close to 100% with the foam. Once you've gotten rid of the boom you'll be onto road noise from the tyres. One day, if I'm feeling adventurous, I might investigate the trim around the wheel arches to see if anything can be done there, as well as doing to doors to help improve sound quality from the Canton system. 

 

Did you get the 19" wheels on yours?

[Alpha2110]

I think the worst that would happen would be that you'd introduce a new rattle until they were replaced.

 

Have a look at my post #897 I've done the entire surface under the boot floor lid thingumy. About 66% coverage with the silentcoat and close to 100% with the foam. Once you've gotten rid of the boom you'll be onto road noise from the tyres. One day, if I'm feeling adventurous, I might investigate the trim around the wheel arches to see if anything can be done there, as well as doing to doors to help improve sound quality from the Canton system. 

 

Did you get the 19" wheels on yours?

So did you notice a difference with the silent coat? I have bought a box and am waiting for the opatunity to install it.

[skd12]

The biggest difference was from fitting it to the boot.

Doing under the rear seat has had a little difference but I've not driven extensively since doing the last bit.

[KarlO3V5]

Following this thread closely as some times the road noise from my wagon is terrible

 

I've got a spare wheel and a rubber boot mat in mine but I think I'll be looking at working by way back to front and also changing the tyre brands when they need doing.

[Schobbeschorle]

So i can tell you the german internet-sites are full of this problem.
I have that terrible noise too, and a lot of others, nobody knows what it is?
Some say putting some Bilsteins in it is the solution, but others say thats no solution

[KarlO3V5]

Drove a friends hatch - non VRS yesterday on its balloon tyres.

 

What a difference it makes - it was near silent compared to my wagon. Time for some matting.

[chellaman]

Collected my new Octavia III 1.4 TSI DSG two weeks ago, and have only done about 500 km due to illness. Bought it mostly on the strength of motoring press reviews and, of course, looks!

In more than 60 years of owning cars and driving everything, although I like the car generally, the dreaded noise annoys me and defeats me.

I'm not sure if it is the same as everyone elses though!

I can only describe it as a lowish-pitch haunting rumbling/droning noise which starts above 20kph and continues thereafter.

It remains at the same loudness and is unaffected by changes of road speed, engine speed, road surface, or anything else!!!

IT IS VERY ANNOYING AND TOTALLY RUINS EVERYTHING ELSE ABOUT THE CAR.

I feel that it can only be a resonance due to air flow, or something else non-mechanical.

Any ideas?

If so, you can find me in the madhouse.

Maybe I'll have to try a soundproofing kit.

[Croat]

Ok. Now I was ****ed off yesterday driving Zagrab -> Zadar the cabin pressure is annoying and definitely now 100% sure a problem driving on highway!

 

Last time I tough I just had a headache but no it was from cabin pressure and noise. My mother was on passenger seat and also her ears ware shut from pressure so it is not only my subjective opinion.

 

 

IDK is this the same issue as topic? I don't get no "boom" sound?

 

Any ideas guys this is really killing the experience of my new car. I don't go on highway to often but still it is killing my ears and head. Also on short trips on highway I didn't experience pressure. Only on longer trips and speeds above 140 to 160 km/h. And I don't plan to drive 130 or less.

Edited 26 May, 2016 by Croat

[Item]

Any ideas?

 

If the car is that new and the sound is that intrusive, I would book the dealer in for a road test and make a strong complaint for starters, especially if this wasn't apparent on your test drive.

 

Show them this thread!

[Gromle]

At what kind of speeds do you experience this booming?

[Item]

Any ideas?

 

Also, presume you checked tyre pressure is at what it should be according to your door plate? Mine were woefully under-inflated from the dealer and many have had theirs overinflated at delivery pressures on collection...

[chellaman]

Hi All,

Took dealers for a spin but they couldn't hear anything!!!!!!

Also went in salesman's own Octavia, and no noise!

I am in Spain, by the way.

My noise starts at 20kph and continues at all speeds above without change in pitch or loudness.

Tyre pressures as book, but have tried others.

Have ordered a soundproofing kit from Nk two weeks ago but no delivery yet.

Will report after fitting.

What a shame to produce such a nice car, then spoil it for a few quids worth of soundproofing!

[triumph61]

I have the same Problems with low frequency Boom. Yesterday i placed my Notebook in the car and take a soundfile. The driving starts at 0.30 and ends 6.13. If its possible use Earphones from Mobile device or Hedaset.

With my HP Pro Notebook and Samsung Earphones i can hear the bumbumbum sound. The Speed was from 20km/h up to 55km/h

 

I uploaded it on my Gdrive

 

https://drive.google.com/open?id=0B5INjAze86wxdGp2TnY0cWlPWms

[Leonblue]

How bizarre. I take it you are referring to the constant bass note thrumming though the car? 

[triumph61]

Yes, it totally aweful.  For some days a car with a small Trailer is driving in front of me, The Trailer was wipping at some parts of the Streets. At same  points in my Car was the boom.

 

The bass note thrumming is much on small streets where composite stone are. ( https://upload.wikimedia.org/wikipedia/commons/thumb/1/13/Drosselweg.JPG/800px-Drosselweg.JPG )

The shock absorber were changed in Juli 2015 in 5q0513049EM.

  Edited 3 June, 2016 by triumph61

[Leonblue]

Yes that would drive me mad too. I've no real idea what's causing that. I would imagine that the suspension is not properly decoupled from the chassis e.g a missing rubber or something touching where it shouldn't. 

Edited 3 June, 2016 by Leonblue

[Item]

So did you notice a difference with the silent coat? I have bought a box and am waiting for the opatunity to install it.

 

Did you get around to installing it yet?

 

I am eyeing up a pack of Dynamat (can't get silent coat in NZ) to line the boot of my estate with. It does get quite boomy and noisey on certain course surfaces even with the spare tyre and I was hoping to tone it down a bit.

 

It is expensive here though I don't want to spend $220 bucks for nothing!