Japanese Used Car Exporter AUTOREC's Official Blog

How to Change Spark Plugs

Spark Plug.JPG

What are spark plugs?

Spark plugs are an essential disposable component in your gasoline engine that creates a spark to combust the fuel and oxygen mixture in the cylinder of your engine in order to move the pistons. Some spark plugs are rated for 100,000 miles (160,000 km), which is fairly unrealistic. I would follow your vehicle's owner manual's guidelines for replacing and inspection of your spark plugs, regardless of if you have these extended life spark plugs in your vehicle. I personally recommend checking the gap on your spark plugs every 30,000 miles (50,000 km)

So there are six tell-tale signs of failing spark plugs:

The engine's idle is rough-
When your car is stationary, your engine should normally idle at around 1000 rpm warm, and give a nice smooth consistent sound.

You are having trouble starting your car-
So if you're not out of fuel, and your battery is perfectly fine, but you can't start your engine, you may have some bad spark plugs, and they are not producing the spark you need to move the engine.

Your engine misfires-
You can tell that your engine has misfired if the engine halts for a fraction of a second and then continues its usual movement.

The engine surges-
When the engine surges, it may cause your vehicle to jerk and then slow down. Or it may cause the vehicle to have a rough stop, because it is sucking in more air than usual in the combustion process.

Your fuel consumption has increased-
Sometimes if your spark plugs have deteriorated, you may notice that your fuel consumption has increased by up to 30% because of the incomplete combustions, it takes more fuel to push the pistons.

Your car lacks acceleration-
It's pretty easy to tell if your car lacks acceleration if you have been driving it for a while. It doesn't respond to the accelerator when you put your foot down, as it used to, or it takes a little bit longer to get the speed up.

So if you see one of these tell-tale signs of failing spark plugs, you may want to get them changed.

But how do you change spark plugs? It's quite easy, depending on the type of engine you have. Most of the time with a 4 cylinder engine, you will have easy access to the spark plugs, but if you have a V6, you may want to take your car to a professional if you can't access your spark plugs, or you are uncomfortable with removing parts to get access to the spark plugs.


  • socket and ratchet set
  • Needle-nose pliers
  • Rags
  • Spark plug gap gauge


  • Spark plugs
  • Anti-seize compound

Once you have gathered your tools and materials you can start replacing your spark plugs.

  1. Locate your spark plugs. There should be 4 to 8 spark plugs in your engine.
  2. Remove the first distributer cap, and only remove one. Your car ignites the spark plugs in a specific order, and mixing the order could be devastating to the engine.
  3. Using the spark plug socket, remove the first spark plug.
  4. Check the new spark plug's gap, and if it is too wide, hit the end on a hard surface, if it is too narrow, widen it with the spark plug gap gauge.
  5. Lubricate the spark plug with anti-seize compound, and install the new spark plug, torqueing to specification.
  6. Lubricate the end of the distributer cap with the anti-seize compound, and replace over the spark plug.
  7. Repeat for the remaining spark plugs.

And you are done. Turn your car on, and make sure everything is ok. If you didn't listen at step 2, when we are only removing one spark plug at a time, you may run into some problems.

And drive awayin your car from Japan!

Happy driving!

Copyright © Autorec Enterprise Ltd. 2015 All rights reserved
Powered by Movable Type