G1 Water Flange - 1.6 (EW) 1.8 (DX,EX)

This coolant flange (coolant outlet) mounts to the cylinder head and provides a connection point for coolant hoses in the engine’s cooling system. It allows hot coolant to exit the cylinder head and flow into the main cooling circuit, playing a vital role in regulating engine temperature and preventing overheating.

On older VW engines these flanges are well known for cracking, warping, or leaking due to age, heat cycles, and constant exposure to coolant. Even a hairline crack can cause persistent coolant loss or air ingress, making replacement essential during cooling system repairs or restorations.

What the part does and how it works

Bolted directly to the cylinder head, the flange seals against the head using a gasket or O-ring and provides hose outlets for coolant flow. As the engine warms up, coolant exits the head through this flange and is routed toward the radiator and heater system. A sound flange ensures:

• Correct coolant circulation

• Stable engine temperatures

• No coolant leaks or air drawn into the system

Key details

• Coolant outlet flange – cylinder head

• Designed for 1.6 and 1.8 water-cooled petrol engines

• Direct replacement for early-style flange used on listed engines

Fitment notes

• Fits EW and EX engines up to chassis number >>15-J-034-000

• After this chassis break, VW changed to part number 037121132B, which is not interchangeable

• Always confirm engine code and chassis number before ordering

Compatible vehicles

• VW Golf Mk1 (1982–1983)

• VW Golf Mk2 (1984–1988)

• VW Golf Mk1 Cabriolet (1982–1993)

• VW Caddy Mk1 (1983–1992)

• VW Scirocco (1982–1992)

• VW Jetta (1982–1991)

Engine codes supported

1.6 engines:

• EW, HN, EZ, HM, PN

1.8 GTI engines:

• DX, JJ, GX, GU, HV, RF, RH, RV

Recommended additional parts

When replacing the coolant flange, it’s good practice to inspect or renew:

• Coolant flange seal / O-ring

• Coolant hoses attached to the flange

• Hose clips

• Fresh coolant/antifreeze