* 2.5L 6-cylinder engine: This engine produced 189 horsepower and 177 lb-ft of torque.
* 3.0L 6-cylinder engine: This engine produced 225 horsepower and 221 lb-ft of torque.
It's important to note that the specific engine in a 2004 BMW X3 will depend on the individual vehicle's trim level and specifications. To determine the engine size of a specific 2004 X3, you would need to check its Vehicle Identification Number (VIN).