Hi everyone,

I've recently acquired a 2002 xj8 SE, automatic, LWB. Full service history and MOT'd and serviced only 3 weeks ago. I've driven it from Edinburgh to London in a couple of days with no problems other than a dirty sensor which was quickly sorted.

It has now started to make an intermittent droning/grinding sort of noise, noticeably around 30mph and going uphill, but it does occur at other times.

I took it to a registered dealer whose mechanic took it for a spin with me in it and couldn't find anything wrong with it! Had it up on the ramps and said the wheel bearings were ok, but if it should happen again to take it back.

It's still occurring, any ideas, and will an 'ordinary' garage be able to sort it?
Not sure if it's the gears, timing belt or what.

Any help would be greatly appreciated!
Many thanks in advance.