Humming, but not bearings

[fatboymal]

Symptoms are a hum from the rear of the car, starts around 25mph and gets louder and higher pitched with speed. Loudest after accelerating to 70 odd then backing off. It's not bearings as both rear discs just replaced. Checked tyre pressures, and no apparent movement/sounds on front bearings.

Any ideas?

 

[welshname]

Symptoms are a hum from the rear of the car, starts around 25mph and gets louder and higher pitched with speed. Loudest after accelerating to 70 odd then backing off. It's not bearings as both rear discs just replaced. Checked tyre pressures, and no apparent movement/sounds on front bearings.

Any ideas?

When the rear discs were replaced were the spacers fitted behind them correctly?

 

[brisa4984]

check balancing first

 

[JON FOZ]

Check the inner edge of your tyres for wear,I've had it a few times over the years,maybe worn rear shocks or wheel alignment

cheers

 

[fatboymal]

Thanks for the suggestions.

When the rear discs were replaced were the spacers fitted behind them correctly?

I don't know, but the noise was the same before the rear discs were changed.

Check the inner edge of your tyres for wear,I've had it a few times over the years,maybe worn rear shocks or wheel alignment


cheers

I'll have a look. The shocks are fairly new, and I don't think there is much adjustment in the alignment on the rear?

check balancing first

Thanks.

I'll head to a local tyre place this morning, check the rear tyres for balance and the wheels for alignment.

 

[Dan@SJM]

What tyres are they?

 

[fatboymal]

What tyres are they?

F1 GSD3s, only around 5K old I think.

 

[Dan@SJM]

Swap the fronts to rears and see if that changes anything.

 

[fatboymal]

Turned out to be a very strange wear pattern to the offside rear tyre. More than a flat spot, there were undulations on the surface of the tyre. So that's that noise solved I reckon.

Also surprised at wear on the front tyres. The tyre fitter I had asked to put the 2 new tyres on the rear of the car last year, who told me that was the wrong thing to do in their opinion obviously ignored my wishes, and fitted them on the front. So two new Goodyear F1s GSD3s, manufactured in June 2013, now with 5K on them, are at 4-2-4mm and 4-3-4mm. Weird thing is I tend to run them a little under inflated, not over.

So given I need 4 new tyres I can chose something other than F1..

 

[scotty2hotty81]

Common complaint, doesn't matter if premium quality or budget, they all do it and it a tyre fault, see it more on bigger cars like mercs and bmws.

 

[masekwm]

I've a weird noise and the garage down the road said it might be the tyres as described above, I thought he was winding me up!

 

[Sparko]

Just had exactly this with a set of 3 yr old T1R's - rears were humming like wheel bearings had gone, turned out to be the tyre surface deforming, almost like large blisters.
Glad you sorted it - I was thinking it was going to be rear disc time again!