I don't see anything listed in the maintenance schedule for the PCV valve for the S60. Is it supposed to be replaced at certain intervals?

 

depending on what year model you have the PCV valve is located right by the oil filter, theres a round cap about 3cm that you can pry off with a sharp screwdriver and inside is an orange rubber disc that gets really gunked up that you should probably clean and make sure it doesn't have a rip in it. If it does they cost about $20 to replace. If the inside of the housing underneath it is really dirty I would try to clean it out best you can without letting any debris fall down in there. Taking the whole thing off is a hassel but getting the air filter box off to get down to it where you can clean it isn't hard at all. They are known for causing problems though and I'd check mine at least every other oil change.