The reason why I believe it is the PCV is because my car makes the exact noise as this guy here:
https://www.youtube.com/watch?v=o9wNM-3f9W4
especially when he turns the engine off @ around 20 seconds, jump to that and you can hear it wheezing out. My car does exactly the same thing.
I do not have access to a new PCV valve to test because apparently there are none in stock in the whole of Australia, I would have to order them from Japan if I wanted to try new ones.