Possible road noise answer.

[meta55b]

I got speaking to a complete stranger the other day. To cut a long story short, we got speaking about cars, he asked what I had. The first thing he asked was, how's the road noise. Do you have a skoda too. "No he said" his friend had one and sold it due to the road noise. Then he says, he thinks he knows the cause to the problem. At this point I was really listening. Especially when he told me what he did for a job, basically he works with sound/vibrations, all round the world. He's never saw under the Octavia only pictures and thinks the problem is the tubular cross member between the two large suspension arms. He told me to give mine a hit with a rubber malet and it will ring like a bell, so I did, he was 100% right. He did start speaking a lot of words I've never heard before, what he thinks is causing the problem but doesn't know the cure without working on an actual car. He was only in town for one day but said he should be back soon. I gave him my number if he does return to have a look at my car and hopefully give me an answer to cure the problem.

[brad1.8T]

Fill it with builders foam?

 

Possibly it vibrates so add some mass to the outside?

[TsvRS]

or strap some dampening to it with circlips?

[TsvRS]

not circlips, coffee must have been odd this morning. I meant band fasteners.

[erindad]

It sounds as if he mean the rear suspension ?

[TsvRS]

I certainly understood he meant the rear suspension and the tubular brace would be the one in the foreground of the picture i.e., towards the front of the vehicle

[alberg]

Maybe some type of rubber in the middle going around the tube to absorbe the vibration....

[meta55b]

I certainly understood he meant the rear suspension and the tubular brace would be the one in the foreground of the picture i.e., towards the front of the vehicle

Yep that's the bit I banged on. I really hope he does come back and spends some time with me on the car.

[trundlenut]

My Octavia is noisy but as it's a 4x4 it doesn't have the big tube, so may well be a red herring.

[redocty]

My octy estate has alway suffered with a drone from the rear, I covered the entire boot floor in Dynamat, and it made a bot of a difference but not much. 

[meta55b]

My Octavia is noisy but as it's a 4x4 it doesn't have the big tube, so may well be a red herring.

You could well be right. Or maybe he's just geussed the wrong part that is causing the problem. I have alway believed it's the rear axle that causes the sound problem and not noise coming through the panels. Is the golf, A3 and seat Leon running the exact same rear set up.

[trundlenut]

You could well be right. Or maybe he's just geussed the wrong part that is causing the problem. I have alway believed it's the rear axle that causes the sound problem and not noise coming through the panels. Is the golf, A3 and seat Leon running the exact same rear set up.

Yes.

[meta55b]

Mmmm. So why is the octy so noisy?????? I was getting my hopes up too.

[pikpilot]

Is this just a Vrs problem perhaps? I say that because my mk2 Elegance is quieter than my mk1 Elegance. Perhaps the Elegance has more sound proofing than other models. Or perhaps it is the low rolling resistance tyres fitted on the 1.6CR to help meet the low emissions target. Just a thought.

[abarth_1200]

I thought the drone was down to the missing sound deadening and the poor geometry. I don't think golfs are as bad because they will have the proper sound deadening and a decent alignment.

[trundlenut]

I'm getting a 4 wheel alignment tomorrow, see if that makes any difference.  Won't help that my tyres are crap though.

[Tilt]

I have reasonable tyres on the estate, and road noise is pretty bad.

Full alignment has been done recently, also, after fitting new console bushes.

[abarth_1200]

The worst tyres to use on the rear of the octy are ones with ribs on the inside portion of tread, continuos band are best, to prevent sawtoothing.

[iaind1]

My vrs hatch really isn't any noisier than a golf.... I'm pretty sure it's not an inherent thing.

[trundlenut]

Well I had the alignment done today and now that the fronts and rears are pointing in the same direction it does seem quieter. Could do with some decent tyres now. With any luck they will eventually wear out to the point where I can justify replacing them.

[Aspman]

GY Efficient grips do make a difference.

[TK699]

As above Goodyear efficient grip made a difference for me too.

[cheezemonkhai]

I posted up on this a while back, but it's easily damped out.

 

Empty your boot and take out the spare wheel.

 

Dynamat (or similar) the spare wheel well and as much of the boot floor as you can be bothered with.

Then cut some underlay (Cloud 9 syuff worked well) in the shape of the boot floor.

 

Put the spare wheel back in, place the underlay down and put the boot carpet back down.

 

Bingo, the noise is much much much less.