146K miles. I have gained so much knowledge and help from this forum. I had been all over this site in regards to my continuing oil leaks, here is my attempt to give back and hopefully help someone else. My oil leak started with the oil filler cap and turbo oil return line. I fixed those gaskets then the dipstick was leaking from the top, I replaced that O-ring, then the dipstick leaked from the bottom where it connects to the oil pan and I replaced that O-ring. These were all very cheap and easy repairs. Next, I developed a big leak coming from the rear main seal. I replaced the vacuum elbows at the intake manifold (by Power Steering pump), and the one at the 3-way connection where the intake almost meets the turbo. Still leaking. Next, I put in Castrol high mileage 10w30 oil (has seal conditioners) got on the highway and got on it, still leaking! I was out of ideas and took the car to my independent Volvo shop. I asked them to check for excess crankcase pressure and verify the rear main was indeed leaking. They recommended a new rear main seal and said that once they start to leak it's time to replace. I asked him about the excess pressure and he said that there was some blockage in my PVC system. I told him I would hold off on rear main repair and for now just unblock/clean the PVC system. I am not sure what they did, but it only cost $30 and fixed the leak. 2 months and 2000 miles, no leaking. Many on this forum have had the same problems, I never delved into the oil seperator because some Volvo expert on this board named Frank says to blow through the tube/hose from the top of the engine (under spark plug cover) to see if it's clear, or blocked. Mine was clear so I didn't remove the intake manifold to investigate further. I hope I can save others from the rear main $eal repair. I wish I knew how they serviced my PVC system, the way the shop described it was like they cleaned out the parts going to the throttle body. When I sprayed TB cleaner into my throttle body 6 months ago to clean it that's when all of the leaks started getting bad.