How To Change Spark Plugs On A 1999 Ford Expedition


Changing your vehicle’s spark plugs is one of the most basic car maintenance jobs, but it can be tricky for some. Luckily, we have an easy way to change them!

Spark plug replacements are usually done when there are signs of poor engine performance such as reduced gas mileage or sluggish acceleration. It is also common to replace old spark plugs because they wear out and cannot fire up the combustion process in a proper manner.

While changing your own spark plugs may not look very difficult, there are several factors that can make this task more complicated if you do not know how to do it. Some people are even legally prohibited from performing these repairs due to safety concerns. That is why it is important to learn about spark plug changes so you are sure you follow all the rules and precautions.

Fortunately, our experts at All Wheel Parts have gathered the information you need to understand and perform a spark plug replacement on your very own vehicle! In this article, we will go over everything you need to know about replacing automobile ignition coil (spark plug) sets. If you have ever wanted to fix or maintain your vehicle yourself, then read on!

Removing And Disconnecting The Plug

We begin by removing the original spark plug and wire assembly before installing a new one. Once completed, we must remember to save both pieces!

To do this, pull off the plastic cover on the top of the cylinder.

Loosen the bolts that hold the engine cover

how to change spark plugs on a 1999 ford expedition

The next thing you will need to do is remove the engine cover! These covers are usually made of plastic or aluminum and lock into place with fastening screws or clamps.

To loosen the clamp, use a thin tool to push down on the screw while pulling up on the engine cover. You may have to work through several layers of seals before getting access to the clamp.

Once it has been loosened, pull straight up to lift off the engine cover. Be careful not to drop the engine cover onto the car body as this could cause damage.

Now that we have removed the engine cover, we can now see all of the spark plugs in our vehicle. It is important to know what size each plug is so that you can get the correct one for your vehicle and how to change them.

Loosen the bolts that hold the engine cover plate

how to change spark plugs on a 1999 ford expedition

Now that you have determined that your vehicle needs new spark plugs, what comes next is changing the spark plugs! The good news is that this can be done at home with some help from professionals.

Spark plug changes are typically done in two steps. First, you will need to loosen or remove the old spark plugs. Then you can install the new ones.

Step one: Remove the old spark plugs

This means taking them out completely. You may want to take pictures before you do it so you know how to put the new ones back together later. Some cars require using a special tool to pull out each individual spark plug.

Some people suggest wiping off the cylinder walls with baking soda first to make sure there’s no buildup. This helps prevent corrosion which could affect the performance of the new spark plugs.

Remove the engine cover

how to change spark plugs on a 1999 ford expedition

Changing your vehicle’s spark plugs is not difficult to do, but it does require some tools and know-how. Fortunately, you can perform this service yourself!

All cars have an ignition switch in the steering column that gets power when the driver turns on the engine. This switch sends electricity through a wire called the distributor, which then distributes the voltage to each of the individual coils (or electrodes) in the combustion chamber where fuel is mixed with air and ignited.

The number and size of the coil or electrode sparks depend on how much gas there is in the cylinder, so if we want our engines to run better, we should be sure they are working correctly. If one isn’t firing properly, no fire will take place, depriving the machine of needed energy.

By changing out the spark plug you get two things: improved performance from better fuel injection and burn efficiency, as well as increased longevity of the part.

Disconnect the battery

how to change spark plugs on a 1999 ford expedition

Changing spark plugs is not something that should be done while the vehicle is running, unless of course you are very skilled in engine repair or have special tools for doing so. Doing it when the car is not working can really hurt your wallet!

If you do decide to change your spark plugs, make sure you only buy new ones from an established vendor. Some companies just sell cheap, poor quality products that fail eventually. An easy way to tell if they are good vendors is looking at reviews online and speak with people who have used their services before.

We will go into more detail about what kind of spark plug you need depending on whether this article has given you any tips!

Reminder: It is extremely important to use the correct tool for removing and installing spark plugs.

Be careful when removing the spark plugs

how to change spark plugs on a 1999 ford expedition

While changing your vehicle’s spark plug, make sure you do it safely. Only use appropriate tools for the job!

Some people cut corners by using low quality equipment or no equipment at all to remove the old spark plugs. These individuals may not put enough pressure on the tool, which could cause damage to the engine.

You don’t want that to happen because then you would have to pay expensive repairs! Removing the old spark plugs correctly will take some time so be prepared!

Reminder: Make sure your hands are warm and dry before working with anything mechanical. If they are, then your chances of doing good work is improved.

Never pull hard on the bolt connected to the spark plug as this can break off in the engine. Also, never drop the spark plug down into the cylinder hole as this can chip or crack the piston.

Replace the spark plugs

how to change spark plugs on a 1999 ford expedition

The next thing you will need is new spark plug wires. You can buy pre-cut lengths of wire at most automotive stores, or you can get them online or from other sellers.

Once you have your length of wire, connect one end to either positive (cranking) electrode in the old spark plug, and then attach the other end to the corresponding negative (grounding) electrode in the engine. Note that it may take some trial and error to find the right length of wire!

You should now be able to test your ignition system by switching on the fuel pump and starting the vehicle. When you turn the key, you should hear a sound similar to someone tapping with a stick on both side of an empty bottle. If you do not, replace the failed spark plug immediately!

Removing and replacing spark plugs is a relatively simple job if you are careful and know what tools to use. Make sure to go slowly when tightening down each spring so as not to damage anything.

Check the coil packs for cracks

how to change spark plugs on a 1999 ford expedition

A lot of people do not realize it, but your vehicle’s electrical system has separate pack systems that contain coils and capacitors. These pack systems are what makes sure your engine functions properly by helping regulate power going into the engine and keeping it running at its best.

If you notice that one pack is looking a little bit thinner than normal, have no fear! You can easily fix this! Simply replace it with an identical one from somewhere else in your car, or even buying new ones!

The most likely place to find bad plugs is in the positive electrode (cathode) pack. If you look closely, you will be able to see if there are several good electrodes surrounded by very thin wires. This does not seem like much, until you try to insert another one into them and they do not go all the way in.

You may also noticed some kind of buildup around the cathodes as well. When conducting electricity, electrons move towards where there are less molecules, so these areas should be pretty empty. If instead you have thick layers of residue, then the electrode cannot hold onto enough electrons which causes poor performance.

Check the air filters for debris

how to change spark plugs on a 1999 ford expedition

While it may sound crazy, replacing spark plugs is one of the cheapest ways to improve your car’s performance. Changing your engine’s ignition system is not expensive, and can increase fuel efficiency by as much as 20%.

Spark plugs are an important part of any vehicle that gets lots of use. They play a crucial role in combustion, which means they influence how fast your vehicle will run!

If you’re looking to boost acceleration, change the “gap” or distance between the spark plug gap and adjacent cylinders. A smaller gap will allow more oxygen into the cylinder, so it’ll take less time for the mixture to burn. This increases combustion speed, and thus acceleration.

Removing old spark plugs and gapping new ones is probably the best way to go about this. You can buy allen key tools that make doing this easy and quick.

Once done, hop onto Amazon or another site and search for “spark plug gap” to find what size gap each engine makes. You want them both within 0.

Leave A Reply

Your email address will not be published.