B4 Passat Water Flange (Rear) - 1996-00 - 1.9TDI (AHU,AFN)

This engine coolant flange is a direct replacement for the unit that bolts onto the rear of the cylinder head on VW Passat B4 models fitted with the 1.9 TDI AHU and AFN engines, manufactured between October 1996 and August 2000. It forms a crucial part of the cooling system, allowing proper coolant flow and hose connection while maintaining a secure seal at the back of the engine.

Made from durable heat-resistant plastic, this flange is designed to withstand high temperatures and pressure cycles common in turbo diesel engines. Cracks, warping, or leaking flanges can lead to coolant loss and engine overheating—replacing a worn or damaged flange helps protect engine performance and reliability.

It’s a bolt-on part that fits with the original mounting and hose layout. A new seal is recommended for installation.

Applications:

• VW Passat B4: October 1996 – August 2000

  • 1.9 TDI AHU engine code

  • 1.9 TDI AFN engine code