High Pitched Squeeling When Coming Off Boost

[StuF]

Good morning,

Today I was driving to work with the window open and noticed a strange noise when coming off boost
Basically when backing off the acclerator I hear a high pitched squeeling noise that sounds like a dry bearing - however the noise only happens when I back off pretty suddenly. Only lasts a second or so like pressure is being released.

Am I correct to assume it is a blocked or semi blocked PCV - car is an 08 GTI, unmapped and isnt loosing any boost when under load.
For interest sakes how much is a replacement PCV?

Many thanks for your help in advance 

[StuF]

I have removed the dipstick with the engine running and the idle doesnt really change although the valve does make quite a noisy hiss
Will have to pop into VW today and grab one and see if that rectifies it!

[StuF]

Fixed - new PCV from GSF for £25! Winner
No more nasty noises