Spark plug wires should not be forgotten when performing routine checkups or while changing your spark plugs.  Better yet, changing the spark plug wires is usually a relatively easy job that you can easily do if you will follow our instructions.  If you feel you have spark plug or spark plug wire problems and you are not comfortable with performing a repair like this, you should definitely get your car into an auto repair shop to be checked and fixed.  A bad spark plug wire could be the cause of that annoying “check engine” light you’ve been seeing.  Periodic changing of your spark plug wires is recommended to ensure your engine runs properly and smoothly.

Find Your Spark Plug Wires

It may sound silly, but you really do need to check out where the wires are located before you get started.  When you are dealing with a 4-cylinder, straight 6, and most of the V8 engines, there usually will not be much of a problem.  You will need to begin with removing the cover over your engine components.  If you see all of your spark plug wires and the access holes, you’re in luck and you can get right to the wire removal and replacement.  If you’re not so lucky and you’re looking into a black abyss, you’ll want to read on.

If all of the plug wires are not easily within your reach, this will take you a little longer.  In many engines half of your plugs will be in a very hard to reach area.  This may require you to remove some of the engine components.  You may want to think about looking for the help of a professional if you are not completely confident in your abilities.

Disconnecting your Air Box

Your air box is the first thing you will want to get out of the way.  This is the box that contains the air filter and then connects to your large intake plenum.  This is what is obscuring the other plug wires you need to access.  Before unhooking ANYTHING, have a really good look at any electrical connections you may have to disconnect.  Be absolutely sure you can correctly reattach everything.  If necessary, draw a diagram or take a quick close-up picture of it to help you.

If the air box connects to the plenum with a large flexible hose, simply remove the clamps securing the hose on each end. Leave the air box in place but remove the hose.  In cases where the hose and air box are together in one unit, you will end up having to unbolt the whole box.

Removing your Intake Plenum

There are multiple electrical connections and other small parts, like nuts, bolts and cables that you will be dealing with here.  You need to take care to pay close attention to detail and allow plenty of time to ensure that you get it done correctly.  Start with removing the electrical plugs.  Don’t forget to make that diagram or take a digital photo of it before you start!  If you have an accelerator cable that runs from the throttle body located on the back of your intake plenum, you will also have to disconnect that.  This is where things start getting rather tricky.  You have to remove all of the parts holding your intake onto the head…yes, all of them.  Again, a quick photo here may be helpful to you when you have to put all this back together.  You need to really take your time with this.  Make sure everything that should be removed has been before you start trying to pull the intake.  When you are ready, it may require a little force since gaskets often have a glue-like effect.

Time to Remove and Replace those Spark Plug Wires!

Now that you have cleared a path for yourself, let’s get to pulling those wires free.  But don’t just jump in and go willy-nilly.  If it has been a while since your spark plugs were changed, you may want to take care of that while you are already changing the wires.  You should replace your spark plug wires one at a time.  This will guarantee that you do not accidentally mismatch any of the connections.  Another little helpful tip is to lay out all of your new wires before you start pulling any old ones out.  This makes it much easier when you need to check that you’re grabbing the right replacement wire.  It is much easier to match length quickly when everything is spread out before you to compare with.