The Infiniti G20 uses a liquid-cooled engine; it has a radiator to store coolant that keeps the engine running at the appropriate operating temperature. The car's thermostat regulates the coolant's flow out of the radiator and through the cooling system.
The thermostat is a small component. The Infiniti G20's thermostat is easy to replace once you access it. Simply pull it out, it's not held in place by any screws.
The thermostat installs to a housing that mounts on the G20's engine. Follow the lower radiator hose to the engine. The hose attaches to a water inlet. The thermostat sits beyond the water inlet, inside the thermostat housing.
You have to remove the lower radiator hose and thermostat housing to access the thermostat. You may have to remove other components depending on your ability to reach the thermostat housing. Skilled mechanics, including home mechanics, are used to working in the confined space of an engine compartment and probably won't have to remove any more parts for access.
