Methods and systems are provided for regulating airflow through a charge air cooler integrated in an intake assembly. In one example, an engine intake assembly comprises a plenum having an integrated charge air cooler (CAC), a first header seal positioned around a circumference of a first CAC header, and a first rotatably movable seal positioned in a bypass passage of the plenum. The first movable seal interfaces via sliding contact with the first header seal and adjusting a position of the first movable seal may vary the amount of airflow through the bypass passage.