Abstract: A co injection manifold assembly for injecting two different materials into a common mold cavity includes a housing that defines a first passage, a second passage and an outlet. The first and second passages communicate with a bore having a valve member for controlling flow of the material through the outlet. A first temperature control element in thermal contact with the first passage and a second temperature control element are in thermal contact with the second passage. Each of the first and second temperature control elements are separately controllable to provide separate temperatures for each of the first and second passages. Separate temperatures in each of the first and second passages provide for the use of materials having dissimilar molten temperatures.