Where is the thermostat on a d4d?

The thermostat on a D4D engine, commonly found in Toyota vehicles, is typically located on the engine block near the water pump. It is usually housed in a thermostat housing, which is connected to the upper radiator hose. To access it, you may need to remove certain components, such as the air intake or engine cover, depending on the specific vehicle model. Always refer to the vehicle's service manual for precise location and removal instructions.