Oil will only be sucked in if the user over oiled it when cleaning. It wont do any harm, oil gets into the intake anyways tuned or stock. even though peopel say oem intake isnt that restrictive, any intake option should increase flow for more hp. I havent heard of any engine failures due to an over oiled filter, most people are afraid of it throwing a code because it covers the maf(for cars with mafs, 335i does not have maf). if you're afraid there is always dry filter options.
Last edited by idrift4wd; 01-23-2013 at 05:00 PM.