I've owned my R53 for about six months. I was doing some preventative maintenance today which involved replacing the intake air filter. The top of the filter element looked clean but the underside was disgusting and looked oil soaked. Here are some pictures: https://imgur.com/a/cgBFVgX.

I cleaned the whole housing with water and a cloth and then vacuumed. So all OK for now. Does anyone have an idea of where that residue came from?

Thank you!

 

It looks like the previous owner sprayed the filter with a filter oil thinking it was a K&N type filter. If the problem persists with the new filter, check your PCV valve. Is the car an S model?

 

Oh man, the thought of that makes me wince. Good idea. I will check the filter housing in another 100 miles or so.

It's an 06 Mini Cooper S, yes. A little over 100,000 miles.

 

yep and wow was that dirty.