Sorry for replying so late. I've replaced the PCV valve (Part number 12204-70020) and a grommet (part no 90480-18001) which holds it as my old one cracked during removal (I'd recommend to order one before you perform any checks on valve). I did follow the manual instructions and my old valve was faulty! And it was all covered in oil. Unfortunately it didn't sort out the problem and i still get the blue smoke on cold starts :( there's no other problems, engine seems to run very smooth and strong (for 150bhp ;) ).
So it seems to be the valve seals after all :( but i'm going to leave it as it is for now. Thanks for help everyone :)