Replacing spark plugs on your Lexus ES 350 is a critical maintenance task that helps ensure optimal engine performance and fuel efficiency. Over time, spark plugs wear out, causing misfires, rough idling, and decreased power. Fortunately, changing them is a straightforward process you can do with basic tools.

When to Replace Spark Plugs

Lexus recommends inspecting the spark plugs every 30,000 miles and replacing them approximately every 60,000 to 100,000 miles, depending on the type of plugs used. If you notice poor acceleration, engine misfires, or reduced fuel economy, it may be time to check your spark plugs sooner.

Tools and Materials Needed

  • Spark plug socket and ratchet
  • Torque wrench
  • Extension bar
  • New spark plugs (check your owner’s manual for the correct specifications)
  • Dielectric grease
  • Anti-seize lubricant (optional)

Step-by-Step Replacement Guide

  1. Allow the engine to cool completely to avoid burns.
  2. Remove the engine cover to access the spark plugs.
  3. Disconnect the ignition coils by unplugging the electrical connectors.
  4. Unscrew the ignition coils and set them aside carefully.
  5. Use the spark plug socket with an extension to remove the old spark plugs.
  6. Check the gap on the new spark plugs and adjust if necessary.
  7. Apply a small amount of dielectric grease to the spark plug boots and anti-seize lubricant on the threads if desired.
  8. Install the new spark plugs by hand, then tighten with a torque wrench to the manufacturer’s specifications.
  9. Reinstall the ignition coils and reconnect the electrical connectors.
  10. Replace the engine cover and start the engine to ensure it runs smoothly.

By following these tips and maintaining your Lexus ES 350’s spark plugs, you can enjoy a smooth ride and extend the life of your engine. Regular maintenance saves you money and prevents costly repairs down the road.