Abstract: In an internal combustion engine air cleaner snorkel having an end open to ambient temperature air and an auxiliary inlet open to heated air, the induction air flow temperature is regulated by a pivoted damper assembly having a guide member positioned by a coiled bimetal and a damper member biased by a torsion spring for concomitant operation with the guide member. The damper member has a main blade portion responsive to the induction air flow rate and controlling ambient air flow and a pair of lateral blade portions controlling heated air flow but unresponsive to the induction air flow rate. Under conditions of high induction air flow the damper member moves away from the guide member against the bias of the torsion spring to permit ambient air flow through the open end and to block heated air flow through the auxiliary inlet.