Low frequency 'boom' in cabin

[ExSEAT]

I had been thinking about this thread the kast few days and wondering why I hadnt seen anything about the 'boom' recently!

 

Im now on my 2nd VRS, the first was a 2016 and the current is the newest facelift MY19 variety.

 

The 2016 presented the boom straight away, I took it back and the tech guy did some work with the stops which reduced it a little. I added some sound deadening in the boot which again reduced it.

 

I hadnt noticed it in the new car, I thought maybe I was so used to it I had zoned it out. 

 

Today was my first time taking it to work and back. There is a section of badly laid shell grip at a level crossing which would set the old car off boomong so bad it was like I had opened the rear windows at 100mph and I couldnt stand it. Today in the new car there was nothing at all.

 

I have noticed that the closing of the rear hatch and the sound it makes is entirely different to the 2016. Its a much more solid and satisfying sound. I dont know if this is the difference or something has changedbut in comparison there is zero boom in this new FL car. 

[antrimman32]

22 hours ago, antrimman32 said:

I googled my issue and found this thread. I have a new model VRs Tdi estate and the booming noise is becoming annoying.

 

Fingers cross its tyre related. Its a lease car and the front tyres when replaced were changed to firestone roadhawks but I think the rear tyres are the issue.

 

Had a puncture and they replaced the rear with a Bridgestone Turanza T005 and the other rear is the original Bridgestone Potenza S001

 

Arrgghhh leasing companies. Surely the tyres are the issue.

 

My question is, I am going to get the S001 replaced. Should I get another T005 and move these to the front and have the evenly worn Roadhawks moved to the rear??

 

 

Update, took car to tyre dealership, they said the original still had good tread dept and he doubted the tyres were causing the boom, he said something like modern steel radials can be mixed and matched without causing my issue.

[antrimman32]

Also I must add, the boom is apparent at low speeds on good roads not rough surfaces.

[Fredosh]

Hi 

I'm new to this forum.

I recently own a seat toledo 2016.

 

First thing I noticed was also the sonic boom. After reading the posts online I also adjusted the boot lid.

It was better for me, but then I unawarely did a second thing which made it better.. 

 

Now, today I noticed that the sound is produced by the back seat, actually the back rest.

If you get on your knees on the back seat and you pound the back rest, it makes the sonic boom. 

It’s like it isn’t sturdy enough.

 

What I found out was that (in my case) you could open the central arm rest in the back,

and the weight distribution of the back rest is different, so it produces a lot less sound.

(The ski opening is still closed.)

So this was the thing I was unaware of, as I had opened the arm rest for a passenger..

 

I think skoda/seat should redesign the backrest.

 

[antrimman32]

On 12/01/2019 at 10:54, antrimman32 said:

 

 

Update, took car to tyre dealership, they said the original still had good tread dept and he doubted the tyres were causing the boom, he said something like modern steel radials can be mixed and matched without causing my issue.

 

After insisting that the noise was coming from the rear original tyre I got the lease company to relent and change the tyre. Immediate difference. I drove along a smooth road and no boom, hurrah!!!!! 

[JohnnyType2]

On 12/01/2019 at 10:56, antrimman32 said:

Also I must add, the boom is apparent at low speeds on good roads not rough surfaces.

 

the biggest culprit is saw toothing on the rear tyres, a common issue on octys

[AGFalco]

And if the tyres are asymmetrical you can try swapping the tyres/wheels from side to side.

You then end up going up the saw tooth edge rather than hitting the sharp/high/noisy edge first.

 

Thanks AG Falco

[MC Bodge]

I recently purchased a 2016 Octavia 1.4 TSI 150 Estate SE-L on 16" rims. New front Nexen tyres (unfortunately) and Rear Eco Contacts (worn apparently evenly)

 

During the (wet) test drive and on the motorway drive home when I collected the car all appeared fine and I was impressed.

 

It is actually a very pleasant car in most senses. The engine is very good (and more grunty than expected). The handling is much better than expected. The interior is also very good, the seats are comfortable and supportive, the whole car appears solid and well assembled. Even the ride over slow big bumps is firm, but not crashy or unpleasant -the low frequency bump response seems acceptable.

 

When I drove the car on bumpy surburban roads, rough surfaces and shell-grip, though, it quickly became apparent that there was a lot of unpleasant noise -Possibly from a number of different sources.

 

There was what sounded to me to be a fairly significant low frequency resonance throughout the car that is generated from the very low amplitude excitation of shell-grip or surface dressing gravel as well as ripples and broken tarmac.

 

There also appears to be a slightly different noise resulting from each side riding over bumps at different times. Driving briskly around a roundabout with shell-grip produces a lot of noise.

 

The high frequency (chatter) bump response appear to be the issue, producing low frequency noises.

 

There is wind noise from the top of the front door window area -a separate issue.

 

Although I've experienced noises in cars before, this is a particularly strange set of noises.

 

I had a look over the car and had a look on the www. It seems that I'm not alone.

 

My findings:

 

The flimsy lower boot covering produces a suspicious low drumming noise when tapped.

The upper boot covering produces a hollow sound when tapped.

The metal boot floor behind the seats produces a low ringing sound when tapped.

The estate boot lid is held evenly and firmly when closed.

 

I put a towel between the lower boot covering and the metal boot floor

I filled the spare wheel well around the space saver wheel with a wool blanket

-The towel and blanket padding appeared to make a bit of an improvement to the noise volume

 

I then (having read about the hatchbacks) tried driving with the estate boot lid ajar. 

-It may have been a placebo effect, but driving along the same section of broken, rippled concrete 4 times at around 15-20mph, twice with the boot closed and twice with it ajar, I am almost certain that the noise and unpleasantness was much reduced with the boot ajar.

 

I'm wondering whether it has something to do with the torsional stiffness of the body, although the resonant frequencies of the estate would probably be significantly different to those of the hatchback.

 

As this appears to be an established issue, are there any recently discovered definitive solutions to the noise/resonance problem?

 

It might benefit from a set of Uniroyal Rainsports or Goodyear Eagle F1, but it might not......

 

 

 

 

 

 

 

 

 

 

 

Edited 21 March, 2019 by MC Bodge

[gregoir]

I've got the same car, but with a spare wheel. Not experienced any of the drumming or ringing.  My hearing is admittedly 25% down.

Extra grip on shell grip will inevitably produce noise.

Edited 21 March, 2019 by gregoir

[MC Bodge]

5 minutes ago, gregoir said:

I've got the same car, but with a spare wheel. Not experienced any of the drumming or ringing.  My hearing is admittedly 25% down.

Extra grip on shell grip will inevitably produce noise.

The shell grip hasn't changed since I drove my old Mk4 Mondeo on it last week, though!

[cr_2dman]

13 hours ago, MC Bodge said:

I recently purchased a 2016 Octavia 1.4 TSI 150 Estate SE-L on 16" rims. New front Nexen tyres (unfortunately) and Rear Eco Contacts (worn apparently evenly)

 

During the (wet) test drive and on the motorway drive home when I collected the car all appeared fine and I was impressed.

 

It is actually a very pleasant car in most senses. The engine is very good (and more grunty than expected). The handling is much better than expected. The interior is also very good, the seats are comfortable and supportive, the whole car appears solid and well assembled. Even the ride over slow big bumps is firm, but not crashy or unpleasant -the low frequency bump response seems acceptable.

 

When I drove the car on bumpy surburban roads, rough surfaces and shell-grip, though, it quickly became apparent that there was a lot of unpleasant noise -Possibly from a number of different sources.

 

There was what sounded to me to be a fairly significant low frequency resonance throughout the car that is generated from the very low amplitude excitation of shell-grip or surface dressing gravel as well as ripples and broken tarmac.

  

There also appears to be a slightly different noise resulting from each side riding over bumps at different times. Driving briskly around a roundabout with shell-grip produces a lot of noise.

 

The high frequency (chatter) bump response appear to be the issue, producing low frequency noises.

 

There is wind noise from the top of the front door window area -a separate issue.

 

Although I've experienced noises in cars before, this is a particularly strange set of noises.

  

I had a look over the car and had a look on the www. It seems that I'm not alone.

 

My findings:

 

The flimsy lower boot covering produces a suspicious low drumming noise when tapped. 

The upper boot covering produces a hollow sound when tapped. 

The metal boot floor behind the seats produces a low ringing sound when tapped.

The estate boot lid is held evenly and firmly when closed.

 

I put a towel between the lower boot covering and the metal boot floor

I filled the spare wheel well around the space saver wheel with a wool blanket

-The towel and blanket padding appeared to make a bit of an improvement to the noise volume

 

I then (having read about the hatchbacks) tried driving with the estate boot lid ajar. 

-It may have been a placebo effect, but driving along the same section of broken, rippled concrete 4 times at around 15-20mph, twice with the boot closed and twice with it ajar, I am almost certain that the noise and unpleasantness was much reduced with the boot ajar.

 

I'm wondering whether it has something to do with the torsional stiffness of the body, although the resonant frequencies of the estate would probably be significantly different to those of the hatchback.

 

As this appears to be an established issue, are there any recently discovered definitive solutions to the noise/resonance problem?

 

It might benefit from a set of Uniroyal Rainsports or Goodyear Eagle F1, but it might not......

 

 

 

 

Hi,

 

i've bought myself a new skoda octavia combi, manufactured 12/2018. i've come to the same conclusion as you. When you drive with the boot lid somewhat open( not locked, in safe mode?). The ride is, lets say, normal (apart from more wind noise).

Also, when you do a test drive, and sit in the rear, you can really hear the vibration,rumbling, low bass sound, coming from the boot area.

as other suggested, i've tried to adjust the rubber boot stopper with 2mm inwards, this solves it for me, however, my wife then cannot stand the car.

 

I personally don't think it comes from the rear axle, as many claim, the torsoin beam setup is widely used, for example a peugeot 308 and will be used in a mazda3,...

 

[mikenippard]

I feel very sorry for you guys who are suffering with this. It is unbelievable that this problem still exists. I bought a new octavia estate in 2014. As soon as i drove away I experienced the low frequecy noise which hurt my ears. I spent six months trying to solve it,  just the same as all of the attempted solutions which have recently been posted. In the end i could stand it no longer and got rid, taking a big financial loss. I personally dont think this will be solved until a brand new design comes on to the market. Good luck

[MC Bodge]

15 minutes ago, mikenippard said:

I feel very sorry for you guys who are suffering with this. It is unbelievable that this problem still exists. I bought a new octavia estate in 2014. As soon as i drove away I experienced the low frequecy noise which hurt my ears. I spent six months trying to solve it,  just the same as all of the attempted solutions which have recently been posted. In the end i could stand it no longer and got rid, taking a big financial loss. I personally dont think this will be solved until a brand new design comes on to the market. Good luck

Annoyingly, I did listen out on the immensely wet test drive and thought that it was ok. A friend with a Mk2 had warned me about the (different) boot noise in his. The reviews I'd read didn't mention the terrible resonance, although I have subsequently found some that do and in A4 and Golfs . 

 

The problem with trawling forums is that problems are often magnified above the reality.

 

Even more annoyingly, my previous car (Mk4 mondeo estate) was excellent in all ways (other than being diesel) and painless to own for 8 years.

 

My car is still under Skoda warranty so will probably need to go to a main dealer for a look at ....for them to shrug, deny there's an issue and claim that they've never seen the problem before....

Edited 22 March, 2019 by MC Bodge

[Sweephand]

19 hours ago, gregoir said:

I've got the same car, but with a spare wheel. Not experienced any of the drumming or ringing. 

 

I had a diesel Scout on PCH for two years (2015 to 2017) and would have gladly got another one if a petrol engine was available. I had a spare wheel, and I didn't experience the noise others have - so is there something in this?

[mikenippard]

No, i had a spare wheel and the low frequncy noise was very evident

Believe me i tried every conceivable fix and nothing worked.

i do agree leaving the tailgate ajar did alleviate the problem, but obviously this not a pratical solution

 

 

[Sweephand]

7 minutes ago, mikenippard said:

No, i had a spare wheel and the low frequncy noise was very evident

Believe me i tried every conceivable fix and nothing worked.

i do agree leaving the tailgate ajar did alleviate the problem, but obviously this not a pratical solution

 

 

 

Ok, thanks for quick reply.

[MC Bodge]

Somebody I know who has a Mk3 Hatch tells me that changing his rear tyres solved a humming noise from the rear of his car -He had suspected that it was a wheel bearing initially.

 

The tread blocks on his rears had become a bit ramped. My car's rear tyre tread blocks feel a little feathered at the leading edges, but nothing major.

 

I'm going to borrow his front wheels (with almost new tyres) and put them on the rear of my car to test it out.

 

Even if it does help, I suspect that I'll add sound deadening. 

 

ps. My wife took the car out and couldn't detect anything untoward.... She was just impressed by it being nicer than her 12 year old Fiesta -which although basic and firm, rides quite well and doesn't crash or buzz over bumps.

 

 

Edited 22 March, 2019 by MC Bodge

[cr_2dman]

15 minutes ago, MC Bodge said:

Somebody I know who has a Mk3 Hatch tells me that changing his rear tyres solved a humming noise from the rear of his car -He had suspected that it was a wheel bearing initially.

 

The tread blocks on his rears had become a bit ramped. My car's rear tyre tread blocks feel a little feathered at the leading edges, but nothing major.

 

I'm going to borrow his front wheels (with almost new tyres) and put them on the rear of my car to test it out.

 

Even if it does help, I suspect that I'll add sound deadening. 

 

ps. My wife took the car out and couldn't detect anything untoward.... She was just impressed by it being nicer than her 12 year old Fiesta -which although basic and firm, rides quite well and doesn't crash or buzz over bumps.

 

 

 

for some reason my wife also doesn't mind at all, i the other hand, goes completely banana over it. :p

However, when i fiddle with the rubber stopper on the boot and set it to 2 lines, instead of 4 from factory, it is better for me, but worse for her :-p

 

The tires on my vehicle are the continental ecocontact 5. i don't think replacing these with other ones are a solution. i am curious to the result.

 

@mikenippard did you try sound deadening like a dynamat in the trunk? i'm thinking of trying this out at a cost of around 200€.

 

also i've noticed this clever ?russian? blogging about:

https://www.drive2.com/l/7023860/

https://www.drive2.com/l/7147142/

 

what are those, and what is the logic/theory behind this?

 

i've found these links in this thread: https://www.briskoda.net/forums/topic/449490-noise-insulation/

 

[mikenippard]

Sound deadaning didnt work for me

[antrimman32]

My car has been perfectly quiet since i changed a rear tyre.

[MC Bodge]

On 22/03/2019 at 20:12, cr_2dman said:

 

for some reason my wife also doesn't mind at all, i the other hand, goes completely banana over it. :p

However, when i fiddle with the rubber stopper on the boot and set it to 2 lines, instead of 4 from factory, it is better for me, but worse for her :-p

 

The tires on my vehicle are the continental ecocontact 5. i don't think replacing these with other ones are a solution. i am curious to the result.

 

@mikenippard did you try sound deadening like a dynamat in the trunk? i'm thinking of trying this out at a cost of around 200€.

 

also i've noticed this clever ?russian? blogging about:

https://www.drive2.com/l/7023860/

https://www.drive2.com/l/7147142/

 

what are those, and what is the logic/theory behind this?

 

i've found these links in this thread: https://www.briskoda.net/forums/topic/449490-noise-insulation/

 

I'm not sure what that Russian blog is showing. It appears to be adding objects inside the car and on the beam???

[MC Bodge]

I didn't bother swapping the wheels today as we decided that the tyres were less worn than the other car's.

 

I did, however, drive the (1.6 D) hatchback back to back with my estate on the same roads.

 

The cars were similar, but the hatch felt softer riding and had much less of a deep thud/boom over bumps and rough tarmac.

 

My car was louder over bumps and ripples and only quiet with the tailgate ajar.

 

The hatchback (with full sized spare) gave a similar bass drum noise when the boot floor was tapped.

 

I adjusted my boot latch fully out and the noise was reduced massively.

-Unfortunately, there was also visible daylight between the tailgate and the body.

 

I didn't adjust the side guides from their original positions.

 

I moved the latch half-way back to the original position and will monitor it.

 

I am intrigued as to what the mechanism is for this booming and why opening the boot makes a difference. It could suggest a pressure issue...

 

Edited 24 March, 2019 by MC Bodge

[cr_2dman]

7 minutes ago, MC Bodge said:

I didn't bother swapping the wheels today as we decided that the tyres were less worn than the other car's.

 

I did, however, drive the (1.6 D) hatchback back to back with my estate on the same roads.

 

The cars were similar, but the hatch felt softer riding and had much less of a deep thud/boom over bumps and rough tarmac.

 

My car was louder over bumps and ripples and only quiet with the tailgate ajar.

 

The hatchback (with full sized spare) gave a similar bass drum noise when the boot floor was tapped.

 

I adjusted my boot latch fully out and the noise was reduced massively.

-Unfortunately, there was also visible daylight between the tailgate and the body.

 

I didn't adjust the side guides from their original positions.

 

I moved the latch half-way back to the original position and will monitor it.

 

I am intrigued as to what the mechanism is for this booming and why opening the boot makes a difference. It could suggest a pressure issue...

 

 

Can you elaborate this: ? Do you mean by side guides, the rubber stops ?

"

I didn't adjust the side guides from their original positions.

 

I moved the latch half-way back to the original position and will monitor it.

"

 

Then for the sound pressure, my family can hear it as well. I have the following theory:

 

I get the part how a trunk door can cause buffeting. I don't really get how the buffeting can also cause a vibration.

 

As for the part of the russian blog, i found this is it the part number:

https://www.volvopartswebstore.com/products/Volvo/Vibration-damper/1137607/30714071.html

 

 

 

 

[MC Bodge]

36 minutes ago, cr_2dman said:

 

Can you elaborate this: ? Do you mean by side guides, the rubber stops ?

"

I didn't adjust the side guides from their original positions.

 

I moved the latch half-way back to the original position and will monitor it.

"

 

Then for the sound pressure, my family can hear it as well. I have the following theory:

 

I get the part how a trunk door can cause buffeting. I don't really get how the buffeting can also cause a vibration.

 

As for the part of the russian blog, i found this is it the part number:

https://www.volvopartswebstore.com/products/Volvo/Vibration-damper/1137607/30714071.html

 

 

 

 

Interesting stuff.

 

My car produces the pressure wave at low speeds, say 15mph+.

 

I adjusted the metal closing latch. See pictures. I didn't adjust the side stops.

 

From looking at that video I initially prevented the seal by unlatching the boot and by moving the latched position outwards before moving it back in a little.

 

What I possibly should have done is retain the seal with the orginal latch position and move the side stops to constrain the tailgate more.

-The tailgate does still feel firmly held anyway, though.

 

I will experiment with the side stops.

 

 

 

[MC Bodge]

That Russian blog appears to show adding weights or simple rubber bushing dampers, presumably to try to change the natural/resonant frequencies of the beam and suspension arms. Interesting and very simple. 

 

The suspension thuds are slightly different to the boom/pulsing from the tailgate issue.