Maintaining your Lexus IS 350 involves regular attention to essential components like spark plugs. Spark plugs play a critical role in igniting the air-fuel mixture inside the engine cylinders, ensuring smooth performance and fuel efficiency. Over time, worn or fouled spark plugs can cause misfires, reduced power, and increased emissions.

When to Replace Spark Plugs

For the Lexus IS 350, it’s generally recommended to replace spark plugs every 60,000 to 100,000 miles, depending on the type of plugs used. Iridium or platinum spark plugs tend to last longer and perform better than traditional copper ones. However, always consult your owner's manual for the manufacturer’s specific guidance.

How to Replace Spark Plugs on a Lexus IS 350

  • Gather Tools: You’ll need a ratchet, spark plug socket, torque wrench, and a gap gauge.
  • Prepare the Engine: Ensure the engine is cool before beginning to avoid burns.
  • Remove Ignition Coils: Carefully disconnect the ignition coils covering the spark plugs.
  • Extract Old Spark Plugs: Use the spark plug socket to remove each plug by turning counterclockwise.
  • Check and Adjust Gaps: Verify the gap on new spark plugs matches specifications using a gap gauge.
  • Install New Spark Plugs: Thread them in by hand to avoid cross-threading, then tighten to the torque specified in the manual.
  • Reattach Ignition Coils: Connect the coils back securely and double-check your work.

Replacing spark plugs yourself can save money and improve your Lexus IS 350’s performance. If you’re not confident in your abilities, consult a professional mechanic to ensure proper maintenance.