What is that chuffing noise!

[tbourner]

I'm getting a rotational chuffing / rubbing noise, sounds a bit like a "wah wah" and appears to match wheel speed. Can hear it at around 27mph usually, also 36 and 45 - which has a worrying hint of resonance about it - above that it's either too high frequency or drowned out by other noises, have only heard something at lower speeds a couple of times but wasn't sure if it was engine/exhaust noises.

Just had all 4 discs and pads done. They needed doing anyway but I was hoping I had a warped disc. Apparently not. Noise is exactly the same.

Before the brakes were done I had vibration when hard braking from *ahem* over 69mph, obviously I haven't tried that just yet on 10 mile old D&Ps, but I'll see if that's been resolved at least.

It seems to get worse after driving around, when the wheels have warmed up - they do warm up quite a bit too, is this normal? I know it's a big heavy auto.

Alignment is perfect, rear tyres are new, front tyres are slightly feathered on the insides, could it be that?
Had a local tyre place get their hands on it and said there's nothing serious going on, no bearing wear showing (yet). Also Olly/PCS did the brakes so it's been looked over. I'm not too worried at the moment it's just very annoying - one of those noises that once you hear it you can't get away from it!

 

[Trickythemerc]

What tyres are on the car ? My CLK was doing this and was on Continentals that had feathering on the inner edges. I was convinced it was bearings having eliminated the park brake cable rubbing on the prop shaft. At tyre change time I went for Dunlop Sport Max RT and the noise was gone.

 

[tbourner]

Yep stock continentals.

 

[renault12ts]

Trevor, I'd agree...tyres.

 

[tbourner]

Hmmmm.... need to consider which tyres to get on the front then! Always used to go for Michelin but it seems Mercedes push for Conti.

 

[wu56Shoozz]

Tyre pressures low or incorrect can cause this.. my Jeep does this when the pressures are low.

 

[PobodY]

Hmmmm.... need to consider which tyres to get on the front then! Always used to go for Michelin but it seems Mercedes push for Conti.

I'm pretty sure you can get Michelin Pilot Sports with an MOE label on them; it might not be the current partnership they're pushing, but I think that's what they approved before switching to Contis.

 

[fifermerc]

I've had this a couple of times with tyre feathering. I was convinced first time it was a wheel bearing but there was nothing wrong with it. Continentals as well in one case. Run your palm around the contact surface of the tyre. If one way feels smooth, the other way rough, as if you were going against fish scales, that indicates feathering of the tyres.

 

[tbourner]

I've had this a couple of times with tyre feathering. I was convinced first time it was a wheel bearing but there was nothing wrong with it. Continentals as well in one case. Run your palm around the contact surface of the tyre. If one way feels smooth, the other way rough, as if you were going against fish scales, that indicates feathering of the tyres.

I know this. Like I said they're feathered on the inside edges on both fronts.

 

[PobodY]

Excessive camber? - Problem with the ackerman angle?