The engine coolant temperature sensor is a small, plastic, plug screwed into the coolant outlet pipe on the front of the engine. It has two wires connected to it.
To locate the engine coolant temperature sensor:
1. Open the hood of your 2004 Mazda RX-8.
2. Locate the thermostat housing, which is located at the front of the engine, just below the radiator.
3. The engine coolant temperature sensor is located on the thermostat housing.
Note: The coolant temperature is not located on the oil filter housing, that is just a dummy sensor.
Here is a diagram of the engine coolant temperature sensor location on a 2004 Mazda RX-8:
[Image of the engine coolant temperature sensor location on a 2004 Mazda RX-8]
