A gas turbine engine having a heat exchanger is disclosed. In one form the gas turbine engine includes a particle separator that can be used to separate particles or foreign objects and create a dirty flow and a clean flow. A blower can be used to discharge the particles or foreign objects from the separator. The heat exchanger includes a relatively warm flow path from a downstream region of a compressor and a relatively cool flow path from an upstream region of the compressor. The relatively cool flow path is merged with the dirty flow. In another embodiment, the gas turbine engine is a turbofan and the relatively cool flow path is merged with a bypass flow. In one embodiment of the engine the relatively warm flow path, after having exchanged heat with the relatively cool flow path is delivered to a working component without passing through a turbomachinery component.