Gloves
Shop Towels
Fender Cover
Wrench
Sockets
Spark Plug Socket
Spark Plugs
Gap Tool
Coil Boots
Dielectric Grease
Torque Wrench
As always—before any job—take a look at your service manual. It's important to know the manufacturer's specifications for your vehicle before getting started. If you don’t feel completely comfortable doing this yourself, call or visit your local O'Reilly store, and we can refer you to a professional technician in your area.
Step 1: Select your workspace, set brake and chock wheels
You’ll start by laying a fender cover across both fenders, or whichever side you plan on doing first, and then disconnect your negative battery terminal.
Step 2: Unplug the coil connectors
Unplug the coil connectors carefully – they may be brittle. If they’re extremely brittle, they need to be replaced. In some vehicles, you may need to gently move hoses or wiring out of the way to give you room to get to the coil connectors.
Step 3: Unbolt the coil hold-down bolt
Unbolt the coil hold-down bolt – there’s usually only one. Once loose, take the coil pack by the housing – not the connector – and gently pull out with smooth, increasing force. You may need to unplug fuel injector connectors if they’re in the way.
Once the connectors are removed from their holes, look in and make sure there's no debris or broken pieces of the coil boot.
Use compressed air or a vacuum to remove all debris before the plugs are removed. This will ensure nothing gets into the cylinders.
Step 4: Remove the spark plugs
Take the spark plug socket that fits your plugs and put it down over the plug, making sure it is fully seated as far down as possible. Loosen the plug by turning it counter-clockwise, and try to keep the socket as straight up and down as possible in relation to the plug. If your socket gets out of alignment, it could crack the ceramic on the plug and cause debris.
Step 5: Check the spark plugs for damage
Look at each spark plug as it’s removed to see if it has any lines that run from top to bottom that won’t wipe off with a rag. If there are lines, this is called carbon tracking, and indicates that you need to replace the coil boot for that cylinder.
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Do It Right: It’s highly recommended that if you remove a spark plug, you replace it – plugs can sustain micro-fractures when you remove them that can cause problems if you continue to use them. |
Step 6: Set the gap on new spark plugs
Once all of the old spark plugs are removed, check the gap using your gap tool to see if the plugs meet the manufacturer's specifications. The metal spokes help you measure gap sizes.
If the gap is too large or small, use the tool to bend the ground electrode down to make it smaller or bend it up away from the center electrode to make it larger. Re-measure the gap to see if you’ve corrected the space. It’s very important not to touch the center electrode or the insulator during this procedure, since they can be damaged.
Step 7: Change the coil boots
When you replace your spark plugs, it’s also recommended that you replace your coil boots. Remember: if you have carbon tracking on one or more of your spark plugs, replacing your coil boots is necessary.
Remove the coil boots. Be sure to wipe off the coil before putting on new boots.
Once you replace the coil boots, set the ignition coil to the side until you’re ready to reinstall them.
Remove the coil boots. Be sure to wipe off the coil before putting on new boots.
Once you replace the coil boots, set the ignition coil to the side until you’re ready to reinstall them.
Step 8: Install the new spark plugs
Gently insert the first spark plug into the socket, making sure it’s fully seated. Then, gently thread it into the cylinder by hand – without power tools – making sure it threads in smoothly. If it isn’t going in smoothly, remove it and check the threads for damage. Then try again, making sure it’s straight.
Step 9: Tighten the spark plugs to torque specifications
Using a torque wrench, tighten the plug to manufacturer specifications, keeping the socket as straight as possible in relation to the plug.
Step 10: Reinstall the ignition coil
Apply a little bit of dielectric grease – cover about ¼” of the coil, where it contacts the top of the plug once in the hole. Gently push downward until the coil is within 1/16” of where it bolts down.
Reinstall the hold-down bolt in the coil.
Reinstall the hold-down bolt in the coil.
Step 11: Replace the coil connector
Replace the coil connector and anything else that you disconnected and move on to the next plug. Repeat these steps until all the plugs are back in place.
If you removed the air filter inlet tube earlier for the sake of space, you can reinstall it now.
If you removed the air filter inlet tube earlier for the sake of space, you can reinstall it now.
Step 12: Reconnect the negative battery terminal
Reconnect your negative battery terminal.
Prime your engine by turning it to the on position before turning it all the way on then start your engine to make sure it runs smoothly.
Prime your engine by turning it to the on position before turning it all the way on then start your engine to make sure it runs smoothly.
Spark Plug Selection
There are a few basic types of spark plugs on the market: basic copper-tipped plug, long-life platinum plugs, and iridium-tipped plugs. Figure out which type is right for your vehicle.
The automotive repair work depicted in this series is performed under the direction of the manufacturer of the product featured. Prior to undertaking any of the demonstrated repairs on your vehicle, we suggest you consult with a certified mechanic or another professional who can adequately advise you of the proper repair or remedy required. O’Reilly Automotive Stores, Inc. and its affiliates (“O’Reilly”) disclaims any responsibility for injury or damage resulting from a viewer’s attempt to recreate the repairs shown in this series.