Firstly, apologies for hijacking a Skoda forum but the Polo 6c/6r are built on the same platform as the Fabia.

 

Hi, wondering if anyone can help me identify the strange noise coming from my BlueGT.

It’s a 17 plate with 64k miles and I changed from my 15” winters to 17” summers a few weeks ago. I thought the car seemed noisier but put it down to the larger wheels. There has been a strange droning/almost rumbling sound which becomes apparent from 20mph. It doesn’t change in pitch nor tone, although is maybe a bit louder at higher speeds but not by much. The noise is there from 20mph upwards and does not change regardless of whether the car is in gear, coasting, under load.

I changed two worn tyres and had them all rebalanced, as I thought it may be tyre roar, but this has made no difference. With the windows down I can’t hear anything coming from outside, there’s no schreeching nor grinding.

I can’t seem to pinpoint where the noise is coming from, as inside the cabin from the driver seat it seems pretty uniform.

Any ideas would be greatly appreciated. Thanks in advance

Did you drive the car on the 17" wheels and tyres before fitting the winter 15" and never notice the noise you hear now.

 

What size tyres are on the 17" wheels, as in how wide, are they 215/40 R17's or something else.

What brand and name of tyres and what pressure are they at?

I don’t remember hearing this noise before, but it had been 6 months since I’d last driven with the 17’s on...

 

215/40 r17, Goodyear asymmetric 5 all round. Had Bridgestones on the rear which had about 3-4mm tread left on, and initially thought it could be them, so I changed them, but the noise is still there. Need to double check pressures but they should be 44psi front 41psi rear (BlueGT eco setting).

 

There was not sign of sawtoothing and had the alignment and balancing checked, and it was all ok.

The noise is quieter on velvety smooth tarmac, but it’s still there. Had thought a wheel bearing or driveshaft bearing on way out, but would that be more noticeable?

 

My child was in the back and thought the noise was coming from my side of the car, but from the driver seat you can’t work out where it’s coming from. There’s no vibration or anything.

As mentioned, it only becomes apparent at 20mph and above.

 

Edited 29 April, 20215 yr by bongobob
More info

I would drop that pressures from the ridiculous ECO pressure for something that might have the car a bit safer on wet roads.

Why would how want less grip / friction and less tread on the ground which is the only way the pressures could have the car use less fuel.

I’ve never noticed a lack of grip, even on wet roads it never has felt skittish.

 

On lower pressure the ride is softer, and it feels more like driving through treacle.

 

I’ll give it a go though, and see if that helps.

 

was just wondering if wheel bearing/driveshaft bearings were a common failure item on this platform...?

They are not a common failure but they can fail.

Your platform and components are really nearer to those on the Fabia Mk3 since 2014.  They got the option of 215/40R 17's when introduced.

(& Mk2 Fabia never got 215/40 R 17 as OEM on the Mk2 vRS but the sister cars as in the Polo Gti, Seat Ibiza Cupra & Audi A1 185ps did.)

 

There have been Fabia Mk3 that have had failures, a member has a thread started just a few days ago about bearings. He is not a happy bunny.

http://briskoda.net/forums/topic/492699-unexpected-problems-on-my-fabia-3-combi

 

Edited 29 April, 20215 yr by e-Roottoot

Thanks for your help folks. 
I’ll repost on the mk3 forums too 👍

17" wheels with fatter tyres will have a harsher, noisier ride and gobble more fuel than the 16" standards. My first thought is if you change back to the smaller winter wheels, does the noise change, disappear or remain? 

That will be my next course of action if lowering the tyre pressures has no effect. At least I’ll know one way or another if it’s the larger wheels/tyres if I put my winter wheels on and test drive it

So I dropped the tyre pressures to the comfort setting, but the noise now became apparent at 10-15mph rather than 20mph when it was at the eco tyre pressures. Put my winters back on and the noise was a lot less noticeable, but if I listen carefully I can faintly hear the noise at the same frequency, but it’s definitely a lot better.

 

Have  swapped my summer tyres from left to right, and will see if that does anything. They’re asymmetric, not directional.

I've just done a Google search for 'VW Polo tyre noise' and guess the result: there's a mass of tyre noise with the Polo reports. The VW forum is full of them.

So I guess that you don't have a fault as such, just an inherent Polo problem. 

Thing is, I’ve done 65k miles in it, and it’s never been something I’ve noticed before. I always was quite impressed with how quiet it was at motorway speeds.

 

What I can’t work out is although the noise virtually disappears with the softer winter tyres on, there is still that faint noise in the background, which is exacerbated by the larger tyres. I would have thought if it was just they tyres then surely swapping them would remove that particular noise at that frequency...it seems odd that two different size wheels and tyres produce exactly the same sound (albeit much quieter)