N54 sludge on oil cap

[AsifLicious]

Hey everyone, last night when trying to figure out where a mysterious sound was coming from, i opened my oil cap and noticed small flakes of what looks like sludge on the oil cap. It's not building up, but there were quite a few of these black little things. Is this normal? I get regular oil changes at 5k miles and use proper BMW oil. Any ideas as to what is causing this?

[slides]

in the cold weather you will get yellow(ish) vapor/sludge on your oil cap if you do a lot of short driving. It will burn off after a while once temps have risin. I use to have it all winter long on my e46's