Audi Coolant Reservoir / Tank / Bottle 8W1121403D

This OEM coolant reservoir, part number 8W1121405J, is a factory-original component designed for Audi vehicles, including the S4, S5 Sportback, and A5 Sportback from the 2017 to 2021 model years. Located under the hood of your vehicle, this reservoir plays a crucial role in maintaining the cooling system's functionality by storing excess coolant and ensuring optimal engine temperature. Commonly referred to as a coolant tank or coolant bottle, its primary function is to hold coolant that circulates through the engine and radiator, preventing overheating. A worn or damaged coolant reservoir can lead to leaks, reduced efficiency, or engine overheating, making timely replacement essential for peak vehicle performance. It is compatible with several Audi platforms, supporting a seamless fit for various engine configurations. Additional part numbers include 8W1121405F, 8W1121405E, and 8W1121405K, ensuring versatile application across similar models. Trust in this authentic OEM part sourced from donor vehicles for reliable performance and quality.