BMW 3.0L A/T (07-13) Water Hose 4way expansion tank thermostat oil cooler heater Water Hose Assembly - Expansion Tank, Thermostat, Auto Trans Oil Cooler, Heater Hose (4-Way Hose) Brand NEW part with full 1 year warranty. BMW part# 17 12 7 548 230, check fit below. Genuine BMW part, recently made: not been lying around. Please see Fitment Chart below, under PRODUCT DESCRIPTION.