2012 S60 T6. Getting a intermittent chriping sound when engine warmed up. Thought it was something with the serp belt/pulleys. Replaced belt, pulley and tensioner. Still makes noise. Another forum suggested PCV system.
Did the glove test and it practically pulled the glove into the engine. The sound comes on soft, builds and then fades. A couple times it did go away when I pulled the oil fill cap. I have ordered a PCV box as everything I've read
says to replace it every 100k for preventative maint. My car as 125K. Any other thoughts? TIA

 

Replaced the PCV box and the chirping is gone.