How To: Replace Spark Plugs On A 2005-2016 Nissan Xterra/frontier With 4.0l Engine

Introduction

This tutorial provides a step-by-step guide on how to replace spark plugs in a 2005-2016 Nissan Xterra or Frontier equipped with a 4.0L engine. Replacing spark plugs is an essential maintenance task that can improve engine performance and fuel efficiency. The estimated repair time is about 1.8 hours. You will need new spark plugs, a throttle body gasket, an upper intake manifold gasket, and optionally, ignition coils.

Step 1: Gather Required Tools and Materials

Before starting, make sure you have the necessary tools and materials:

• Spark plugs (e.g., NGK LFR5AGP)
• Throttle body gasket
• Upper intake manifold gasket
• Optional ignition coil (e.g., Hitachi IGC0006)
• Basic hand tools (ratchet, sockets, wrenches)
• Torque wrench
• Screwdrivers
• Pliers
• Clean rag or shop towels

Tips

• Always check your vehicle's manual for specific torque specifications.
• Use a spark plug socket for easier removal and installation.

Step 2: Prepare the Vehicle

1. Disconnect the Battery

   • Remove the negative terminal from the battery to prevent electrical shorts.

2. Remove Engine Covers

   • If applicable, take off any plastic engine covers to access the intake manifold.

Step 3: Remove the Intake Manifold

1. Remove Throttle Body

   • Disconnect the throttle body connectors.
   • Unbolt the throttle body from the intake manifold and set it aside.

2. Disconnect Various Hoses and Cables

   • Detach any hoses or cables connected to the intake manifold.
   • Label them if necessary for easier reinstallation.

3. Unbolt the Intake Manifold

   • Loosen and remove the bolts securing the intake manifold.
   • Carefully lift the manifold off to expose the spark plugs.

Common Pitfall

• Ensure all hoses and electrical connections are removed before attempting to lift the manifold to avoid damage.

Step 4: Replace the Spark Plugs

1. Remove Old Spark Plugs

   • Use a ratchet and spark plug socket to unscrew each spark plug.
   • Keep track of the order in which you remove them.

2. Install New Spark Plugs

   • Apply a small amount of anti-seize compound to the threads of the new spark plugs.
   • Hand-tighten the new spark plugs into their respective holes and then torque them to the manufacturer’s specifications.

Important Note

• Do not overtighten the spark plugs as this can cause damage to the engine.

Step 5: Reassemble the Intake Manifold

1. Install New Gaskets

   • Place the new upper intake manifold gasket and throttle body gasket in their respective positions.

2. Reattach the Intake Manifold

   • Carefully lower the manifold back into place and secure it with bolts.
   • Torque the bolts to the manufacturer's specifications.

3. Reconnect Throttle Body

   • Reattach the throttle body and reconnect its connectors.

4. Reconnect Hoses and Cables

   • Reconnect all previously detached hoses and cables, ensuring a secure fit.

Step 6: Reconnect the Battery and Test

1. Reconnect the Battery

   • Reattach the negative terminal to the battery.

2. Start the Engine

   • Start the vehicle and let it idle. Check for any unusual noises or leaks.

3. Test Drive

   • Take the vehicle for a short drive to ensure everything is functioning properly.

Conclusion

Replacing the spark plugs on your Nissan Xterra or Frontier can enhance engine performance and fuel economy. By following these steps, you can successfully complete the task on your own. Remember to regularly check your vehicle’s maintenance schedule for future spark plug replacements and keep your tools handy for any other automotive needs.