Hi all. I have a 2023 Karoq Prestige 1.4 tsi 150 hp fwd. It is one month old at 700 km.

 

I am generally pleased with it except when I drive it on roads made with interlocking concrete tiles (which, to my luck, compose two-thirds of the town I live in), it slowly starts to make a kind of vibration noise at 15 km/h, which increases to a loud roaring cabin resonance at 22 km/h, then goes away after 30 km/h.
It has stock 18" summer tires on (Goodyear Eagle F1 Asymmetric 5). I tried different pressures (36, 34, 33 psi) but didn't make a difference.

 

We tried my friends' cars on the same road and within the same speed range:
*2017 Vw Polo 1.2 with Continental Premium Contact 2 made the exact same noise.
*2016 Vw Golf 1.4 tsi with Continental Premium Contact 6 made no noise.
*A 30 year old Renault 9 made no noise.

 

On other roads it is just the usual tire noise and stiff suspension thuds, which, I guess, to be expected in a C-SUV with torsion beam suspension at the rear. 

 

Do you have any ideas what may be causing this noise and what can I do to narrow it down?

22km/h divided by the pitch of the concrete tiles equals the resonant frequency (or multiple) of the bodyshell or more likely the least rigid panel the roof panel.

 

 

Edited 22 July, 20232 yr by J.R.

Is there anything that can be done to deaden it?

Would it make any difference to change the tires in your opinion?

@Gayrisafiwelcome to the forum.

 

Which country are you in and is this a 1.4 TSI with an 8 speed automatic gearbox?

 

Edited 22 July, 20232 yr by toot

@tootI am in Turkey. It is a 1.4 tsi fwd with 7 speed dry clutch dsg gearbox.

6 hours ago, Gayrisafi said:

Is there anything that can be done to deaden it?

Would it make any difference to change the tires in your opinion?

Yes, add mass and/or stiffness to the panel that is resonating

 

No, no difference.

Gayrisafi, does that low speed noise occur with other cars you've been in or owned?

 

There's probably no easy fix.  Some sort of low frequency air volume or panel resonance is taking place, excited by vibration from the tyre tread hitting that particular road surface, but it is often difficult to establish which panel or air volume can be causing a particular boom.  The vibration is of course transmitted through the tyres and then the car suspension mounts & bushes.  Most tyres these days, in UK at least, are XL rated, with reinforced side walls that makes them more robust at surviving knocks and scrapes, but this reduces sidewall flexibility and probably makes noise transmission from the tread greater, but there are supposedly a few (or there were) non XL tyres around and I would have liked to fit some.

 

I suspect also your Prestige has low profile tyres and some years ago, having tried a 4WD Karoq with 19" wheels and finding too much road noise, I did go for a basic SE (tech) 2WD model with 17" wheels that I found somewhat more serene.  I recently went further & changed to even smaller 16"wheels with correspondingly higher profile tyres, but many would think that changing wheels or even just changing tyres is a step too far, though I enjoy tinkering around with such things.

 

I'm actually particularly fussy about any sort of road induced noise - it's an interest or is it an obsession - I just find road noise tiring. and in cars I've had over the last 10 years or so, have always taken measures like damping panel resonances with bitumen pads, in addition to wheel & tyre changes, in order to reduce this - sometimes successful, but not always.  Worked well with my Karoq anyhow after some trial and error, with low frequency drumming noticeably reduced (even if it still intrudes a little now & again), but then it was a fairly quiet car to start off with.

 

I suspect the Karoq Prestige has the rear seats that can lift out, which means there is only a roll up fabric cover closing off the boot from the car interior.  The cheaper variants with fixed seats like mine have a more solid shelf which partially limits noise transmission from the boot, where road noise often comes from.