A heat exchanger assembly comprising: a first manifold and a second manifold spaced from said first manifold; each of said manifolds (22, 24) having a tubular wall and a pair of manifold ends spaced from each other defining a flow path and each of said manifolds (22, 24) having a width defined within said tubular wall; a plurality of flow tubes extending between said manifolds (22, 24) and in fluid communication with said flow paths for communicating a heat exchange fluid between said manifolds (22, 24); an inlet port defined by said first manifold and an outlet port defined by at least one of said manifolds (22, 24) for communicating the heat exchange fluid to and from said heat exchanger assembly; an insert slidably disposed in said flow path of said first manifold and having a pair of insert ends with a directing surface extending between said insert ends; a pair of side flanges integrally extending opposite each other from said directing surface toward and along said tubular wall for orienting and securing said insert in said flow path of said first manifold; and a separator integrally extending from one of said insert ends of said insert toward said tubular wall obstructing at least a portion of said width of said first manifold for directing the heat exchange fluid through said heat exchanger assembly characterized in that said tubular wall of said first manifold defines at least two indentations with each indentation spaced from and opposite the other with said side flanges mechanically engaging said indentations for further orienting and securing said insert in said flow path of said first manifold. a first manifold and a second manifold spaced from said first manifold; each of said manifolds (22, 24) having a tubular wall and a pair of manifold ends spaced from each other defining a flow path and each of said manifolds (22, 24) having a width defined within said tubular wall; a plurality of flow tubes extending between said manifolds (22, 24) and in fluid communication with said flow paths for communicating a heat exchange fluid between said manifolds (22, 24); an inlet port defined by said first manifold and an outlet port defined by at least one of said manifolds (22, 24) for communicating the heat exchange fluid to and from said heat exchanger assembly; an insert slidably disposed in said flow path of said first manifold and having a pair of insert ends with a directing surface extending between said insert ends; a pair of side flanges integrally extending opposite each other from said directing surface toward and along said tubular wall for orienting and securing said insert in said flow path of said first manifold; and a separator integrally extending from one of said insert ends of said insert toward said tubular wall obstructing at least a portion of said width of said first manifold for directing the heat exchange fluid through said heat exchanger assembly characterized in that said tubular wall of said first manifold defines at least two indentations with each indentation spaced from and opposite the other with said side flanges mechanically engaging said indentations for further orienting and securing said insert in said flow path of said first manifold.