A cooling system includes a housing having an aperture intersecting a passage that includes first and second passage portions. A plug is arranged in the aperture in an interference fit in a first position at a first temperature condition to block the passage and fluidly separate the first and second passage portions. A biasing element is arranged in the housing and is configured to move the plug from the first position to a second position at a second temperature condition to fluidly connect the first and second passage portions.