Engine Coolant Thermostat for BMW N55

The Wahler 11537601158 is an OEM-quality engine coolant thermostat assembly, manufactured in Germany, designed to regulate your BMW's coolant flow and maintain proper operating temperatures. Thermostats are crucial for engine health; a failure in the 'open' position can lead to a cold engine, rich fuel mixture, poor mileage, and carbon buildup, while a failure in the 'closed' position can cause dangerous overheating and potential engine damage. Symptoms of a failing thermostat include an overheating engine, the engine not reaching optimal running temperature, or the radiator fan not engaging. This Wahler thermostat is specifically designed for BMW models equipped with the N55 engine, often referred to as "TwinPower Turbo." It is a direct replacement for BMW part number 11537601158. For optimal service, it is recommended to replace the electric water pump concurrently with this thermostat to save on labor and ensure a thorough cooling system overhaul. **Important Fitment Exclusions:** This thermostat is NOT for cars before the 2011 model year. It is also NOT compatible with cars featuring the N54 twin-turbo engine or "F" chassis BMWs. **BMW Fitment includes (but is not limited to):** * E82/E88 1 Series (2011-2013) 135i, 135is (N55) * E90/E91/E92/E93 3 Series (2011-2013) 335i, 335xi (N55) * E84 X1 (2014-2016) X1 35i xDrive * E70 X5 (2011-2013) X5 xDrive35i (N55) * E71 X6 (2011-2013) X6 xDrive35i (N55)