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How to Change Spark Plugs

The humble spark plug has changed very little over the years—and changing them is as simple as ever.


  • Step 1: Let car cool down Park your car and wait for it to cool down. This may take a few hours, since the spark plugs are among the hottest parts of your engine.
  • Step 2: Locate spark plugs Pop open the hood and locate your spark plugs by referring to your owner’s manual.
  • Step 3: Remove one spark plug Remove one spark plug wire from the end of the row by pulling its boot, or the little cap where it connects to the engine -- not by yanking on the wire itself.
  • TIP: You can also use a spark plug wire puller to easily detach the wire.
  • Step 4: Attach spark plug to socket wrench Attach the spark plug socket to the socket wrench. You may need to use a swivel joint and/or a socket wrench extension to reach the spark plug.
  • Step 5: Remove spark plug Remove the spark plug by turning the socket wrench counterclockwise.
  • Step 6: Make sure hole's clean Make sure that the spark plug hole is clean. If necessary, use a rag and rubbing alcohol or compressed air to clean the spark plug hole.
  • Step 7: Install new spark plug Carefully install a new spark plug into the empty hole and tighten it by hand.
  • Step 8: Secure new spark plug Use the socket wrench to secure the new spark plug in place.
  • Step 9: Reconnect spark plug wire Reconnect the spark plug wire onto the new spark plug.
  • TIP: Changing your spark plugs one at a time prevents incorrect installation that can affect the car’s timing and engine performance.
  • Step 10: Move on to next spark plug When you have successfully changed a spark plug, move on to the next one until you have finished installing all new plugs.
  • FACT: Diesel engines don’t use spark plugs.

You Will Need

  • A vehicle owner's manual
  • New spark plugs
  • A socket wrench
  • A spark plug socket
  • A socket wrench swivel joint
  • And a socket wrench extension
  • A spark plug wire puller
  • A cleaning rag
  • And rubbing alcohol

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