Oil Separator Ventilation Valve Diaphragm Membrane with 3.6 V6, 4.8 V8 Engines It is necessary to select the membrane precisely according to the original oil separator number, since in the original only the complete oil separator is supplied, we manufacture and sell the membrane separately !!! The diameter of the membrane is 87.5mm. Please verify the part number on your vehicle before ordering. Original oil separator numbers: 94810713520 94810713521 94810713522