Humming Noise Seat Leon Cupra 280 after 50 km/h

[Sam_p_m]

Hello,

I’ve been dealing with a humming noise for quite a while now. It starts whenever I go above 50 km/h and becomes noticeably louder around 120 km/h. At higher speeds, the general road noise starts to mask it.

Last year, I had a bad front left wheel bearing replaced by a garage. After that, I ordered two SKF bearings for the rear axle and one FAG bearing for the front from Amazon.

This year, both rear SKF bearings turned out to be bad, so just yesterday I replaced them with two FAG bearings ordered from Autodoc. Unfortunately, the noise is still there.

Here’s what I’ve tested so far, but I still can’t find a clear cause:

• Driving side to side to see if the noise changes - no difference.
• Went under the car with a stethoscope and checked both front wheel bearings - couldn’t notice any obvious difference.
• Checked the wheels for play (up/down and side-to-side) - no play.
• Swapped to a different set of wheels with winter tires - the noise remained.

I’m still open to the possibility that it’s a wheel bearing, but I can’t find any clear indication pointing to one specifically.

Any ideas or suggestions would be greatly appreciated. Thanks!

I've added a video of the noise: Seat Leon Cupra 280 Humming Noise

 

[James_R]

Are the tyres ok and not stepped on the inner edges?

 

[SRGTD]

I had a noise that sounded like a bad wheel bearing some years ago. Turned out it was sawtooth / stepped tyre wear (a.k.a ‘cupping’) on the inside edge of the rear tyres; apparently not that uncommon on cars with independent rear suspension. If your tyres are suffering from sawtooth tyre wear, if you run your hand around the inside of the tyre tread, you will probably be able to feel the stepped tread wear. In particularly bad cases, you can also see it.

You can see a picture of sawtooth tyre wear in the second post of the discussion topic at the link below;

REALLY LOUD INTRUSIVE TYRE/ROAD ROAR

From my 7k old PS4S's on my 2018 Cupra R. So bad I suspected a wheel bearing issue. It does vary with speed and road surface. Makes my ears numb. Seems rears mainly. Any suggestions. I have a roll of unused sound proof felt. Going to start with boot floor separator panel I used to put it under...

www.seatcupra.net

 

[SuperV8]

When my front bearings failed, the 'feint' noise was more a rhythmic whump whump whump, only noticeable above 50mph, and got louder the faster I went - rather than a constant drone/hum like your noise. It was only ever a feint noise - for example the wife couldn't hear it, but I could.
There was never any noticeable play when I tried the usual MOT wheel play assessment, and they didn't feel rough.

I finally determined it was my bearings - and not tyres, when I pulled into my road with my windows down and I heard a brake squeak noise when I turned in. (couldn't hear it with the windows up).

I could recreate this noise - on hard turning, the brakes would let out a little squeak - meaning there must be some bearing play for the discs to run out of true and contact the pads, but not enough to be felt by hand.
I changed both front bearings which cured the noise.

 

[RUM4MO]

Lucky for some being able to use FAG, in my wheel bearing posting on another forum it got changed to ***, so I wised up and used F-A-G always after that!
I’ve used my hand to check for sawtoothing on tyre treads, gently rub/run your hand round the tyre in one direction then do the same in the other direction, if there is significant sawtoothing you should feel it in one direction more than in the other.
I agree that replacing both wheel bearings at once is the best plan.

Edit:- I’d trust both SKF and FAG, as long as they had been fitted using the correct tools/method.

 

[Sam_p_m]

Thank you so much for the feedback, guys. I went for a quick drive today after the replacement of the 2 back wheel bearings yesterday, and things seem to have changed. I've also tested by changing the front wheels Left-right and the right-left.

The only thing I hear now is road noise, which is loud in this car :/.

I've made a small video, please check it and tell me what you think:

 

[nd-photo.nl]

Tyre choice has a tremenduos effect on road noise, might also be worth looking into. Cheap tyres tend to have a hard compound, which is terrible for road noise.

Other things to consider:
-Adding alubutyl matts to the doors
-Adding alubutyl matts to the boot area

ND-Photo.nl 's - Seat Leon ST Cupra 280

Changed the coolant expansion tank. After re-ordering a couple of times, I just went with the Nissens one. I thought it was a "G12" version and not a G13 with the silica bag. I removed the bag off course before fitting it. Cap was also swapped out. Cheap item and its a mechanical item in the...

www.seatcupra.net

-Adding alubutyl matts under the rear seats

ND-Photo.nl 's - Seat Leon ST Cupra 280

And the divertervalve has been upgraded as well. I went with the Go Fast Bits (GFB) DV+ T9381 instead of the T9351, which still utilizes the stock divertervalve. The T9381 is a full 1:1 replacement which I prefer. 24Tuned gives a nice personal touch to their orders, I like that. The top hat can...

www.seatcupra.net

 

[Pinky]

I've also had the humming rear tyres thing before.

 

[RUM4MO]

A random posting, maybe linked to this:- is there not an "Audi only" rear mounting that effectively kills some of these noises known to affect all non Audi marque versions of these cars, it is a long time since I read about it, and considered approaching my older daughter to fund me to swop bits on her 2019 Cupra 290 - but I didn't move forward on that.

 

[SuperV8]

A random posting, maybe linked to this:- is there not an "Audi only" rear mounting that effectively kills some of these noises known to affect all non Audi marque versions of these cars, it is a long time since I read about it, and considered approaching my older daughter to fund me to swop bits on her 2019 Cupra 290 - but I didn't move forward on that.

You mean the mass damper fitted to the A3 FWD multilink rear subframe?
1K0 505 563

 

[nd-photo.nl]

You mean the mass damper fitted to the A3 FWD multilink rear subframe?
1K0 505 563

View attachment 54244

Never seen that before Interesting!

[edit]
Just found this:

How to retro-fit the rear subframe harmonic damper from the Audi A3 Saloon (2013->)

Disclaimer:- This info is for community usage. I am NOT affiliated to, or sponsored by, any company/individual to promote them or their products. Companies/individuals may NOT use my name, photos, or threads/technical guides, for financial or personal gain (fraudulent misrepresentation). Part...

www.golfmk7.com

[edit 2]
Images from a random ebay offer

 

[tracktoy]

Nor me, This is defo on the list of things for me to do as I don't have any rear seats

 

[SuperV8]

Never seen that before Interesting!

Only fitted to the earlier MQB A3's - checking 2017> they don't have it either - so bean counters have been sticking their fingers in!

 

[tracktoy]

again.

 

[RUM4MO]

You mean the mass damper fitted to the A3 FWD multilink rear subframe?
1K0 505 563

View attachment 54244

That's it!

 

[nd-photo.nl]

I could not stop myself and put the car on the lift and took a picture

2x Mounting holes in my 2015 Leon ST rear subframe

 

[mungo]

Check to see how hot the wheels are after a drive. Is one hotter than the other? If so, could be a rear caliper sticking. I recently replaced mine due to this (and pads and discs!)