Revs climb from idle when warm

[rdj001]

Hi,

have a 2006 MK5 GTi - Since last night, when the car is warm the revs at idle will constantly climb to around 2k and then drop back to about 800 rpm. The only other apparent change in behaviour is I think I can now hear a slight whistle (air leak?) under load.

Aside from that, car is driving perfectly, no loss of power.

Any ideas gratefully received.

Thanks
Rod

[andrewparker]

Needs a new PCV valve by the sound of it. Quite simple to do, parts are about £45.