A heat exchanger that includes an extruded core member defining a plurality of spaced apart flow passages. The core member has first and second sides, one of said first and second sides defining a first set of flow openings communicating with the flow passages and one of said first and second sides defining a second set of flow openings communicating with the flow passages. A first unitary end cap connected to the first end of the core member has a first member sealing the first flow passage ends of at least some of the flow passages, and a second member extending from the first member partially over the side of the core member defining the first set of flow openings and defining at least one flow path between at least some of the first set of flow openings. A second unitary end cap connected to the second end of the core member has a first member sealing the second flow passage ends of at least some of the flow passages, and a second member extending from the first member partially over the side of the core member defining the second set of flow openings and defining with the core member at least one flow path between at least some of the second set of flow openings.