* Most Common: On the passenger side (right side) of the intake manifold, near the thermostat housing. It's usually a smaller sensor than other sensors in the area.
* Less Common (but possible): On the cylinder head. This is less frequent on this model year, but it's a possibility.
To find it definitively:
1. Consult a repair manual: A Haynes or Chilton manual specific to your 2002 Ford Expedition will show you exactly where the sensor is located for your specific engine. This is the most reliable method.
2. Use a parts diagram: Search online using your vehicle's year, make, model, and engine size. Many parts websites (like AutoZone, Advance Auto Parts, etc.) have online diagrams that show the location of the sensor.
3. Visually inspect the engine: With the engine cool, look closely around the thermostat housing and the intake manifold on the passenger side. The sensor is usually a single-wire or two-wire sensor with a connector.
Caution: Always ensure the engine is cool before working around it. Coolant is hot and under pressure when the engine is running and can cause severe burns.
