C30 r-design revving at 1500rpm

[ricsamdan1]

Anyone that can give me some advise.

I have a 2010 C30 r-design and this morning it started doing something odd.
It is revving between 1000 and 1500 rpm and goes down to normal and then back up again, it also started making a funny noise from the engine bay. Almost like a whining hissing noise and then it goes away and comes back???

I open the bonnet and the sound doesn't sound like it is coming from the turbo (my first thought) but rather from the front air box where the throttle body connects to.

Any suggestions or ideas??