97 Civic Ex air filter question
 

I just checked my daughter's Civic for oil and a clean air filter and
noticed a round black greasy pattern on the bottom of it(the paper
fins). I know the round shape is due to the air inlet after the filter
pulling air in but the greasy black stuff surprised me.

I'm thinking their must be a leak somewhere near that is blowing oil
from the engine in small amounts into the air filter.

Does anyone have any experience or opinions on this issue?

Thanks guys!

Ron T