Buy OEM Audi Part # 4D0121403C (4D0-121-403-C, 4D0121403A, 4D0121403B). Engine Coolant Reservoir. 3.7 LITER. 4.2 LITER, 1997-99. 4.2 LITER, 2000-03. Engine Coolant Expansion Tank - Repair or Replace A failed

Engine Coolant Reservoir.
A container that holds Engine Coolant.

Engine Coolant Reservoir

Fits A8, S8

3.7 LITER. 4.2 LITER, 1997-99. 4.2 LITER, 2000-03.
Engine Coolant Expansion Tank - Repair or Replace
A failed expansion tank can cause the cooling system in your Audi to leak antifreeze, or it can cause your engine to overheat. If you're losing coolant, contact our service department to avoid engine damage.