Maintaining your Mitsubishi Eclipse Cross in peak condition involves regular upkeep, and one critical aspect of this routine is replacing the spark plugs. Spark plugs are essential components responsible for igniting the air-fuel mixture inside the engine’s combustion chambers. Over time, spark plugs can wear out, become fouled, or develop gaps that are too wide or too narrow, leading to engine misfires, decreased fuel efficiency, rough idling, and diminished overall engine performance. Proactively replacing spark plugs at recommended intervals helps ensure your vehicle runs smoothly, maximizes fuel economy, and minimizes harmful emissions.

Why Replacing Spark Plugs is Important for Your Mitsubishi Eclipse Cross

The Mitsubishi Eclipse Cross features a modern, efficient engine design that relies heavily on precise ignition timing and combustion. Spark plugs play a vital role in this process by producing the small, controlled electric sparks needed to ignite the compressed air-fuel mixture. When spark plugs degrade, several performance issues can arise:

  • Engine Misfires: Faulty spark plugs may fail to ignite the mixture properly, causing the engine to misfire. This results in jerky acceleration, hesitation, and uneven power delivery.
  • Reduced Fuel Efficiency: Worn spark plugs can lead to incomplete combustion, meaning more fuel is consumed to produce the same power output.
  • Difficulty Starting the Engine: Spark plugs in poor condition may make it harder to start the engine, especially in cold weather.
  • Increased Emissions: Inefficient combustion can increase the release of unburned hydrocarbons and other pollutants.
  • Potential Engine Damage: Persistent misfires and rough running can harm other engine components over time.

Replacing spark plugs at the intervals specified in your Mitsubishi owner’s manual helps avoid these issues, maintaining your Eclipse Cross’s reliability and longevity.

Mitsubishi recommends inspecting or replacing spark plugs generally every 30,000 to 60,000 miles, depending on the type of spark plug used and driving conditions. Iridium or platinum-tipped spark plugs often offer longer service life compared to conventional copper plugs. However, always refer to your specific model year’s owner manual or service guide for exact recommendations. If you frequently drive in severe conditions such as extreme temperatures, dusty environments, or stop-and-go traffic, earlier replacement may be beneficial.

Tools Needed for Replacing Spark Plugs on a Mitsubishi Eclipse Cross

Before beginning the replacement procedure, gather the following tools and supplies to ensure a smooth and effective job:

  • Spark Plug Socket: Typically a 5/8" or 13/16" socket designed with a rubber insert or magnetic core to securely hold the spark plug during removal and installation.
  • Ratchet Wrench with Extension: Provides leverage and reach to access spark plugs that are recessed deep within the engine bay.
  • Torque Wrench: Essential for tightening spark plugs to the manufacturer’s specified torque value, preventing damage from over-tightening or loosening.
  • Gap Gauge or Feeler Tool: Used to measure and adjust the spark plug electrode gap to the exact specification.
  • Dielectric Grease: Applied to the inside of the spark plug boot to prevent moisture intrusion and ensure a strong electrical connection.
  • Anti-Seize Compound (Optional): Applied sparingly to the spark plug threads to prevent seizing or galling in the cylinder head, though some manufacturers advise against its use—consult your owner's manual.
  • Compressed Air or Small Brush: For cleaning debris and dust around the spark plug wells before removal to avoid contamination inside the combustion chamber.
  • Protective Gloves and Safety Glasses: To protect your hands and eyes during the procedure.

Preparation and Safety Tips

Before you begin the spark plug replacement process, keep the following in mind to ensure safety and prevent vehicle damage:

  • Work on a Cool Engine: Always allow the engine to cool down completely before starting. Spark plugs and engine components become very hot during operation, and working on a hot engine can cause burns or damage the spark plug threads.
  • Disconnect the Battery: For added safety, disconnect the negative terminal of the battery to prevent accidental electrical shorts.
  • Work in a Well-Ventilated Area: This prevents inhalation of any fumes or dust stirred up during the cleaning process.
  • Organize Removed Parts: Keep track of all spark plug wires or ignition coil connectors to ensure they are reinstalled in the correct order.

Step-by-Step Technique for Replacing Spark Plugs

Follow this detailed procedure to replace the spark plugs on your Mitsubishi Eclipse Cross:

1. Remove the Engine Cover

Depending on your Eclipse Cross model and engine layout, an engine cover may conceal the ignition coils and spark plugs. Remove this cover by unscrewing bolts or releasing clips as needed, setting it aside carefully.

2. Clean the Spark Plug Area

Use compressed air or a soft brush to clean the area surrounding each spark plug well thoroughly. This step is crucial to prevent dirt, dust, or debris from falling into the combustion chamber when the spark plugs are removed, which could cause engine damage.

3. Disconnect Ignition Coils or Spark Plug Wires

Carefully unplug the ignition coil electrical connectors or spark plug wires. For coil-on-plug systems common in newer Mitsubishi models, gently release the retaining clips and pull the coil straight up. Avoid twisting or pulling on wires to prevent damage.

4. Remove Old Spark Plugs

Attach the spark plug socket to the ratchet with an extension if necessary. Insert it carefully into the spark plug well, ensuring it grips the spark plug firmly. Turn counterclockwise to unscrew and remove the old spark plug. Be cautious not to drop the plug or damage the threads.

5. Inspect and Prepare New Spark Plugs

Before installation, check the gap of each new spark plug using a gap gauge or feeler tool. The correct gap for the Eclipse Cross spark plugs is typically between 0.032 to 0.044 inches (0.8 to 1.1 mm), but always verify with the owner’s manual or service manual for your specific model.

If the gap is incorrect, gently bend the ground electrode to adjust it without damaging the center electrode or insulator.

6. Apply Dielectric Grease and (Optionally) Anti-Seize

Apply a small amount of dielectric grease inside the spark plug boot. This helps prevent moisture ingress and ensures a solid electrical connection. If you choose to use anti-seize, apply a very thin layer to the spark plug threads to aid future removal, but confirm this aligns with Mitsubishi’s recommendations to avoid over-tightening errors.

7. Install New Spark Plugs

Carefully thread the new spark plug into the cylinder head by hand. This prevents cross-threading, which can cause permanent damage to the cylinder head. Once finger-tight, use the torque wrench to tighten the plug to the manufacturer’s specified torque, usually around 13 to 18 lb-ft (18 to 25 Nm) for the Eclipse Cross, but verify the exact value for your engine.

8. Reattach Ignition Coils or Spark Plug Wires

Reconnect the ignition coil or spark plug wire to the plug. Make sure the connection is secure and the retaining clips are engaged properly.

9. Repeat for All Spark Plugs

Continue the process for each cylinder, ensuring all plugs are replaced and tightened properly. The Mitsubishi Eclipse Cross typically features a four-cylinder engine with four spark plugs to replace.

10. Reinstall the Engine Cover

Once all spark plugs are replaced and ignition coils or wires reconnected, reinstall the engine cover by securing any bolts or clips removed earlier.

Testing and Final Checks

After completing the spark plug replacement, reconnect the battery if it was disconnected. Start the engine and listen carefully for smooth idling without hesitation, knocking, or misfires. Monitor the dashboard for any warning lights. If the engine runs rough or a check engine light appears, double-check all connections and spark plug installation torque.

Additional Tips for Maintaining Your Mitsubishi Eclipse Cross Ignition System

  • Inspect Ignition Coils: While replacing spark plugs, check ignition coils for signs of wear, cracks, or corrosion. Faulty coils can cause misfires even with new spark plugs.
  • Use OEM or High-Quality Spark Plugs: Always opt for genuine Mitsubishi spark plugs or reputable aftermarket brands designed for your vehicle to ensure optimal performance and longevity.
  • Keep Records: Log the date and mileage at which spark plugs are replaced to maintain accurate maintenance records.
  • Address Engine Issues Promptly: If you notice symptoms such as rough idle, poor fuel economy, or difficulty starting, inspect the ignition system components early to prevent further damage.

When to Seek Professional Assistance

Replacing spark plugs is a manageable task for many DIY enthusiasts with basic mechanical skills and proper tools. However, if you encounter any of the following situations, it’s advisable to consult a certified Mitsubishi technician:

  • Difficulty accessing spark plugs due to engine layout or modifications.
  • Stripped or damaged spark plug threads in the cylinder head.
  • Persistent engine misfires or diagnostic trouble codes despite spark plug replacement.
  • Lack of proper tools, such as a torque wrench or spark plug socket.
  • Uncertainty about spark plug type, gap specifications, or torque settings.

Professional technicians have specialized knowledge, diagnostic equipment, and experience to ensure your Mitsubishi Eclipse Cross ignition system is serviced correctly and safely.

Conclusion

Regularly replacing the spark plugs on your Mitsubishi Eclipse Cross is a fundamental maintenance task that ensures your engine continues to run efficiently and reliably. Using the correct tools, following the proper procedures, and adhering to manufacturer specifications will help you achieve optimal results. Whether you choose to perform this maintenance yourself or entrust it to a professional, keeping your ignition system in top shape contributes to the overall health and performance of your vehicle for miles to come.