A heat exchanger system is provided having a heat exchanger with a first inlet. A first outlet is fluidly coupled to the first inlet by a plurality of first channels. A second outlet is fluidly coupled to the first inlet by a second channel, the second channel having a first portion arranged transverse to the plurality of first channels. A bypass valve having a second inlet fluidly coupled to the first outlet and a third inlet fluidly coupled to the second outlet, and a third outlet selectively fluidly coupled to the second inlet and the third inlet, the third outlet being fluidly coupled to the first inlet. When in a bypass mode of operation, the thermal transfer medium flows through a channel in the heat exchanger to de-congeal the oil within the plurality of first channels.