At peak power and mainly noticable in 1st,2nd,3rd there is a sort of rumble that can be heard for a second or so.

Imagine hitting the rumble strip on the inside on the motorway. That same sort of frequency and not a million miles away for noise to be fair.

Could this be the DMF on its way out or worn?

Edited 30 September, 201114 yr by Fred44

Dmf is usually rattly at low rpm

Can be heard at idle.... Then if you put your foot on the clutch noise should dissapear

I think a noise at high rpm is when you've reached the speed of sound

Is it not the torque limiter?

It sometimes does rattle at idle and yes putting the clutch down stops it.

Torque limiter?

Thanks for the replies by the way!!