To find it, you'll need to:
1. Consult a repair manual: A Chilton's or Haynes repair manual specific to your 1998 Chevy Cavalier will have a diagram showing the exact location of the coolant temperature sensor. This is the best and most reliable method.
2. Look near the thermostat housing: This is the most common location. The thermostat housing is usually near the top of the engine block, on the passenger side (right side when looking at the engine from the front of the car). The sensor is often a single-wire or two-wire sensor screwed into the engine block, relatively close to the thermostat housing.
3. Visual Inspection (with caution): Once the engine is cool, carefully examine the area around the thermostat housing. Look for a sensor that's connected to a wire harness and is likely screwed into a threaded port. Be careful not to touch anything hot or get burned.
Important Safety Note: Always ensure the engine is completely cool before attempting any work on it. Coolant is hot and under pressure when the engine is running, and can cause serious burns. If you are not comfortable performing this task yourself, take your car to a qualified mechanic.
