Infiniti FX45 2003-2008 4.5L V8 Engine Specifications

The 4.5L V8 engine in the 2003-2008 Infiniti FX45 produces 315 horsepower and 329 lb-ft of torque. It features a DOHC design with 32 valves, a compression ratio of 10.5:1, and a redline of 6,500 RPM. This engine is compatible with premium unleaded fuel and is paired with a 5-speed automatic transmission. It is designed for optimal performance in both city and highway driving conditions.

Regular maintenance for the 4.5L V8 engine includes oil changes every 5,000 miles, air filter replacement every 15,000 miles, and spark plug replacement every 60,000 miles. Additionally, the timing belt should be inspected every 30,000 miles and replaced every 90,000 miles. Coolant and transmission fluid should be flushed every 30,000 miles to ensure optimal engine performance and longevity.

Replacing the 4.5L V8 engine requires professional tools and expertise. Begin by disconnecting the battery and draining fluids. Remove the intake manifold, exhaust system, and accessories. Unbolt the engine mounts and transmission connections, then carefully lift the engine out. Install the new engine by reversing the steps, ensuring all connections are secure. Torque bolts to manufacturer specifications and refill fluids before testing.

If the engine misfires, check spark plugs, ignition coils, and fuel injectors. For overheating, inspect the coolant level, radiator, and thermostat. Unusual noises may indicate worn timing belts or bearings. Use an OBD-II scanner to diagnose error codes. Regular diagnostics and timely repairs can prevent major issues and ensure smooth engine operation.

To optimize performance, use high-quality synthetic oil and premium fuel. Upgrade the air intake and exhaust systems for better airflow. Regularly clean the throttle body and fuel injectors. Consider a performance tune to enhance horsepower and torque. Proper tire pressure and alignment also contribute to overall vehicle efficiency and engine performance.