Engine squealing noise..
 

Today my 2007 s40 started making a squealing noise. I started researching on the internet and found some info on the oil/air seperator. I pulled out the dipstick and the noise went away, so I now know that is the problem. How do I change this part, and where can I purchase it?

Isn't this under warranty? If so, just get to a dealer and let them fix it...

https://volvoforums.com/forum/volvo-s40-11/whining-noise-oil-tank-pressure-issue-41465/?highlight=valve