Abstract: The invention relates to a method for producing a radiator box or charge air cooler box in the form of a plastic box with an integrated seal by means of two-component injection molding using an injection molding tool. The injection molding tool includes a first main part, a second main part and a movable sliding element core as the third main part, the parts forming a first cavity for at least one part of the plastic box and, by a relative movement of the movable sliding element core, a second cavity, immediately adjacent to the first cavity, for a seal material.