What debris have you found in a used oil filter?

[MarkStock]

Since a lot of folks here cut open their used oil filters, I'd be interested to understand what quantity of debris did you find that was not stuck in the media?

I'm trying to establish whether there is anything to be worried about in terms of bypass location.

 

[HTSS_TR]

If you change your oil with reasonable interval for your driving condition and if the filter does its job, then you will not see much if anything with naked eyes, assume that your engine is clean.

 

[ZeeOSix]

2004 Nissan Altima with 3.5L V6. 5000 OCIs, with Mobil Super 5000 5w30 oil. Pureone filter. I cut open and inspect with light and a 10X magnifying glass. I see a few aluminum particles, and mostly small chunks of carbon. I can take these chunks and smear them on a white piece of paper, and they disintegrate, so I concluded they are carbon based debris. Sometimes, a small chunk of gasket material or plastic from the chain tensioners will be in the filter. IMO, it all looks like normal wear in an engine like this.

Everything I saw inside the filter was stuck in the media. This filter sits perfectly horizontal when mounted to the engine. Filter bypass valve in the dome end.