Vehicles using Z24i engine list:

Engine Z24i, used in the Nissan Pathfinder / Terrano 2.4i 2WD (1990–1995), is a reliable 2.4-liter inline-4 engine but, like any older engine, it has some common issues that owners should be aware of. Understanding these problems and their solutions can help maintain engine longevity and performance. 1. **Overheating and Cooling System Issues** Diagnosis: Frequent overheating can be caused by a failing thermostat, clogged radiator, or a weak water pump. Check for coolant leaks, radiator blockages, and ensure the radiator fan operates correctly. Prevention: Regularly flush the cooling system and replace coolant every 2 years or 30,000 miles. Inspect hoses and clamps for wear. Solution: Replace faulty thermostat or water pump promptly. Clean or replace the radiator if clogged. Ensure the radiator fan motor and temperature sensor are functioning. 2. **Valve Cover Gasket Leaks** Diagnosis: Oil leaks around the valve cover area are common due to gasket aging. Look for oil seepage on the engine top and check for burning oil smell. Prevention: Regularly inspect the valve cover area during oil changes. Solution: Replace the valve cover gasket to prevent oil leaks and potential engine damage. 3. **Ignition System Wear** Diagnosis: Misfires, rough idling, or hard starting can be caused by worn spark plugs, distributor cap, or ignition wires. Prevention: Replace spark plugs every 30,000 miles and inspect ignition components regularly. Solution: Replace spark plugs, distributor cap, rotor, and ignition wires as needed to restore smooth engine operation. 4. **Timing Chain Tensioner Wear** Diagnosis: A rattling noise from the front of the engine, especially on cold starts, may indicate timing chain tensioner wear. Prevention: Regular oil changes with the correct grade help maintain tensioner longevity. Solution: Replace the timing chain tensioner and inspect the timing chain for wear if noise persists. 5. **Fuel System Issues** Diagnosis: Hesitation or poor fuel economy can result from clogged fuel injectors or a dirty fuel filter. Prevention: Use quality fuel and replace the fuel filter every 30,000 miles. Solution: Clean or replace fuel injectors and replace the fuel filter to improve fuel delivery. In summary, regular maintenance including timely oil changes, cooling system care, ignition system checks, and fuel system upkeep will help keep.