OE 06B121111K Thermostat Assembly with Built-in Sensor for Direct Replacement on Audi A4 and VW Passat Engine Coolant Thermostat

This Thermostat Assembly with OE numbers 06B121111K and 06B121111H is a core cooling system component specially compatible with Audi A4 and Volkswagen Passat. It precisely controls coolant circulation to keep the engine running at the ideal working temperature. When the engine is cold, it stays closed to speed up warm-up; once reaching the preset temperature, it opens to guide coolant to the radiator for heat dissipation.

Made of premium heat-resistant plastic and high-precision internal elements, this assembly effectively solves common failures such as engine overheating, slow warm-up and poor heating output. It is manufactured strictly following OE specifications, ensuring stable sealing performance and long service life. Complete with built-in sensor and sealing gasket, it supports direct replacement without extra modification. It is an ideal aftermarket replacement for auto repair shops and car owners to restore cooling system reliability and protect the engine from thermal damage.