Genuine BMW Coolant Expansion Tank

The Genuine BMW Coolant Expansion Tank (also called a coolant reservoir, coolant overflow tank or radiator expansion tank) is an original equipment part made to BMW specifications. It is a key part of the engine cooling system. It holds excess coolant as the engine heats up and cools down, and it gives the system room to expand and release pressure.

Key Features:

• Original equipment part designed and validated by BMW for its engineered cooling systems
• Holds coolant and allows for thermal expansion during engine operation
• Helps keep coolant level and system pressure stable for reliable engine temperature control
• Molded from durable, coolant-resistant material built to handle repeated heat cycles
• Made for the OE fit, finish and connection points, so it installs without modification

A cracked, leaking or discolored expansion tank can cause coolant loss and overheating. Replacing it with a Genuine BMW part restores the OE sealing and performance of the cooling system. Select the child item that matches your application to get the exact part number.