[s-cars] Urgent.. UrS4 vibrates when turbo should kick in...

[Ivan Demkovitch]

Folks,

Today I noticed that when on WOT car would start jerk at about 3-4k. Right 
when it should have boost. And it did it on all gears - can't let me 
accelerate fast. It would drive fine otherwise. Hour later I was driving and 
everyting was fine. It was fine earlier today..

What is that could be?

Is it something dangerous? I'm planning on driving 500 miles tomorrow and 
wonder what that could be...

Thanks,
Ivan