JL 078-121-121 K Engine Coolant Thermostat Housing

The JL 078-121-121 K is an engine coolant thermostat housing designed as a direct replacement for Audi and Volkswagen vehicles equipped with 2.4L, 2.7T, and 2.8L V6 engines. This critical cooling system component houses the thermostat and connects to the engine block, helping regulate engine temperature and maintain optimal coolant flow.

Construction and Materials:

• Manufactured from durable ABS plastic material designed to withstand high engine bay temperatures and hot coolant exposure
• Engineered to OEM specifications for precise fit and reliable performance
• Made in Germany to ensure quality standards

Key Features:

• Direct replacement for OEM part number 078 121 121 K
• Replaces worn or cracked original housing that can lead to coolant leaks and overheating issues
• Easy installation with exact fitment to original mounting points
• High-temperature resistant construction for long service life

Important Installation Note: This housing does not include the sealing O-ring (part number N 901 368 02), which should be ordered separately and replaced during installation to ensure a proper seal.

Over time, exposure to constant heat cycling can cause the original plastic thermostat housing to become brittle, crack, or develop leaks. Replacing a failing thermostat housing prevents coolant loss and helps maintain proper engine operating temperature, protecting your engine from damage.