2017 Ford Expedition Engine: 3.5L V6 GAS; Position: Alternator and Water Pump;. 2015 Ford Expedition Engine: 3.5L V6 GAS; Position: Alternator and Water Pump;. Part Type: Serpentine Belt. 2016 Ford Expedition Engine: 3.5L V6 GAS; Position: Alternator and Water Pump;.