I've just noticed my previous post only displayed the first line - so here goes another try!

Basically, my 420 saloon which has only done 47k and recently passed the MOT test has a disconcerting roaring-rumbling noise from the front, which changes pitch and volume instantaniously dependant upon the texture of the road surface and diminishes a little as the tyres warm up and almost disappears if the road surface is really smooth.

Now for the weird bit - the noise disappears completely irrespective of road surface and tyre temperature if I have a front seat passenger!

I've checked for play in the wheel bearings and drive shafts and they appear to be absolutely fine, and checked everywhere for "loose" components which could vibrate or flap about etc.

Regarding the tyres, they are Uniroyal RainSport 5's having covered about 10k miles in just over three years, and are still less than half worn.

Pressures are correct having checked with three seperate guages! The handbook states the front and rear tyre pressures as 32psi and 30psi respectively - but the Haynes Manual says 35psi and 32psi. I must say the front tyres do look to be under-inflated at 32psi, but that may be by design of course.

I know tyres have a noise rating, so perhaps someone can comment accordingly or has experience of using this make and type. Any suggestions where to look next would be most appreciated.

Regards to all,

Stan.

Hi Stan,

Things I'm sure you've checked, assume no uneven tyre wear from tracking problems. Do you get the same symptoms if you swap the wheels front to back? As they are rain tyres, they may have a specified direction of rotation, an outer side marked on them.

Hugh

Hi Hugh,

Thanks for your suggestions. Yes, the tyres have to be fitted a certain was round which all checks out, ant they have been checked for damage and concentricity etc.

It would be worth double checking the tyres are not out of shape - jack the car up and spin the wheel rapidly, looking across the tyre tread for a rise & fall as it spins.

When I was in the motor trade we had a fair few customers come in complaining of a wheel bearing type noise, which actually was one or more tyres being out of shape. Budget tyres were particularly prone, but so too were Pirelli P6000’s (urgh) and some Continentals.

My other thoughts are possibly a worn engine or gearbox mount transmitting excessive vibration into the cabin.

I take on board what you advise, and I'm working at it!