G2 Thermostat Housing - 1.1,1.3

This high-quality thermostat housing with base seal is a direct replacement for the original plastic housing used on Volkswagen’s early small-capacity water-cooled engines. Over time, the original housings commonly become brittle, warped or cracked due to heat cycling and coolant exposure, leading to leaks, poor temperature regulation, or overheating. Replacing the housing restores the integrity of the cooling system and ensures the thermostat is properly seated for correct coolant flow.

The housing fits all 1.0 and 1.3 VW water-cooled engines of the era, including HZ, AAK, MH, NU, NZ and early 2G types. These engines rely on the thermostat housing not only as a coolant junction point but also as a sealing surface that ensures the thermostat opens and closes at the correct temperature. A worn or distorted housing can cause coolant seepage, fluctuating temperatures or long warm-up times.

This replacement housing includes its base sealing ring, ensuring an airtight and watertight fit with no need for additional sealant. It is manufactured from high-strength moulded plastic designed to withstand modern coolant formulations and long-term thermal stress.

When fitting, it is recommended to:

• Inspect the thermostat for wear (replace if in doubt)

• Check coolant hoses for cracking or swelling

• Flush and refill the cooling system with the correct coolant mix

To Fit Engine Codes

• HZ – 1.05

• AAK – 1.05

• MH – 1.3

• NU – 1.3

• 2G – 1.3 (up to chassis >>1G-L-990 000)

• NZ – 1.3 Digijet

Confirmed Vehicle Fitment

VW Golf Mk2 (1984–1992)

• 1.0 & 1.3 water-cooled engines

VW Polo Mk1/Mk2 (1982–1990)

• 1.0 & 1.3 petrol engines

Suitable for all early Polo and Golf small-block engines using the classic bolt-on thermostat housing.