The invention concerns a method for operating a gear pump, in particular for delivering engine oil in an oil circuit of a vehicle, wherein a delivery device is provided with at least two gear wheels, in particular with external toothing or configured as spur gears and arranged in a housing, wherein by means of the gear wheels a fluid to be conveyed can be delivered starting from at least one housing inlet through to at least one housing outlet, and wherein the gear wheels are arranged behind each other viewed in the axial direction (x). According to the invention, an adjustment device is provided, by means of which the gear wheels can be twisted and/or displaced relative to each other depending on the pressure conditions inside the housing, in particular depending on the vacuum pressure at the housing inlet and/or depending on the fluid back-pressure at the housing outlet.