One or more techniques and/or systems are disclosed for bypass flow filtering. A bypass valve filter includes at least one wall configured to engage a surface of a bypass valve and a filter surface having a plurality of openings between an inside of the at least one wall and an outside of the at least one wall. One or more openings of the plurality of openings have a first size and one or more other openings of the plurality of openings have a second size, wherein the first size is different than the second size to define different levels of filtering. The bypass valve further includes an open end configured to allow fluid flow therethrough and to the plurality of openings.