The Pierburg Auxiliary Water Pump - 702078390 is a small, electric pump designed to circulate coolant through the engine's cooling system. It is typically used in vehicles with turbocharged or supercharged engines, as these engines generate more heat and require additional cooling. The pump is responsible for maintaining a steady flow of coolant to prevent overheating and ensure optimal engine performance. It is a crucial component in the overall cooling system and helps to regulate the engine's temperature. The Pierburg Auxiliary Water Pump is a reliable and efficient solution for keeping your engine running smoothly.