Engine Coolant Reservoir. Expansion tank.
A container that holds Engine Coolant.
Engine Coolant Reservoir
Fits 740i, 740i xDrive, 745e xDrive, 840i, 840i xDrive
3.0 LITER, INNER RADIATOR. 740i. 740i xDrive. 745e xDrive.
Engine Coolant Expansion Tank - Repair or Replace
A failed expansion tank can cause the cooling system in your to leak antifreeze, or it can cause your engine to overheat. If you're losing coolant, contact our service department to avoid engine damage.