T25,G2,G3 Thermostat Cover - Diesel Engines

This plastic thermostat housing flange bolts onto the top of the thermostat housing and is designed to seal the thermostat while providing a single outlet for the coolant hose. Supplied complete with the correct sealing gasket, it is a direct replacement for worn, cracked, or leaking original flanges.

On diesel Type 25 (T3) engines, this flange forms a critical part of the cooling system, directing coolant flow from the thermostat into the cooling circuit. Over time, heat cycling and ageing coolant can cause the plastic housing to warp or crack, leading to coolant leaks and poor temperature control.

Replacing the flange restores correct sealing and reliable coolant circulation.

Fitting notes: Always clean mating surfaces thoroughly before installation. Inspect hose condition and clips, refill with the correct coolant, and bleed the cooling system after fitting.

Vehicle Fitment

VW Type 25 / T3 Diesel

• 1.6 Diesel (50–70PS): 1981–1992

• 1.7 Diesel (57PS): 1985–1992

• Bus, Van & Platform/Chassis variants

VW Golf Mk2

• 1.0 & 1.3 Petrol: 1983–1992

VW Golf Mk3

• 1.3, 1.4 & 1.6 Petrol: 1991–1999

• Hatchback & Estate

VW Jetta Mk2

• 1.3 Petrol: 1984–1991

VW Polo

• Polo 86C Petrol: 1983–1994

• Polo 6N Diesel (1.7 & 1.9): 1996–2001

VW Vento

• 1.4 & 1.6 Petrol: 1991–1998

Other Applications

• VW Caddy II 1.9 Diesel Pickup (1996–2000)

• VW Lupo 1.7 Diesel (1998–2005)

• VW Passat B5 1.6 & 1.8 Petrol (1996–2000)