I've seen multiple posts about this issue but always seem to come to a dead end. Any suggestions? These are the steps I have taken...
i removed the oil pan and cleaned out a large amount of build up, and replaced the (disgusting looking) filter and ran new oil through. I also put some of that car detergent to hopefully clean out more of the build up. It ran fine for about a mile and then I got the issue again. My next step is to try to replace the o-rings, but I'd like to know that I'm approaching this in a correct way. If anyone has had similar issues and found a fix, please share! If I figure out the culprit I will update the post to hopefully help others.

2004 Volvo s60 2.4 (no turbo) 118k miles