S4 B6 avant manual vibration

[Jacko123456]

Hello I am new to this forum as I was hoping someone might be able to help me with some technical information. 
I have a 2004 S4 B6 avant manual, last week it developed a really nasty vibration when driving and also if sat stationary when revving the engine, does not happen when idling. I think it’s the dual mass flywheel but everyone I have been to say it’s not that as it isn’t noisy and the pedal doesn’t jump when pressure is applied to the clutch. Has anyone had such a problem before? Many thanks