How to Change Spark Plugs

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


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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


  1. 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.

  2. Step 2

    Locate spark plugs

    Pop open the hood and locate your spark plugs by referring to your owner’s manual.

  3. 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.

  4. You can also use a spark plug wire puller to easily detach the wire.

  5. 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.

  6. Step 5

    Remove spark plug

    Remove the spark plug by turning the socket wrench counterclockwise.

  7. 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.

  8. Step 7

    Install new spark plug

    Carefully install a new spark plug into the empty hole and tighten it by hand.

  9. Step 8

    Secure new spark plug

    Use the socket wrench to secure the new spark plug in place.

  10. Step 9

    Reconnect spark plug wire

    Reconnect the spark plug wire onto the new spark plug.

  11. Changing your spark plugs one at a time prevents incorrect installation that can affect the car’s timing and engine performance.

  12. 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.

  13. Diesel engines don’t use spark plugs.