How Long Does It Take To Change Spark Plugs? [Complete Guide]

Spark plugs, despite their diminutive size, perform a significant function. To ensure that your engine runs properly, you’ll want to know how often you should replace your spark plugs and how long it would take if ever you’re in a rush.

Replacing spark plugs on an engine with four cylinders takes roughly an hour and saves you at least $100 in labor costs if you do it yourself.

It’s usually a simple task that will help you keep your engine running smoothly and obtain the highest gas mileage possible.

Here in this article, you will be reading all about spark plugs. The topics covered here include how a spark plug works, cases of when you need to change it, and how to change it with a 7-step procedure.

What Is A Spark Plug And How Does It Work?

So, what is the definition of a spark plug? The ignition system of a vehicle is incomplete without a spark plug.

This small insulated device ignites the air and fuel mixture inside the cylinder using high-voltage electricity to generate a tiny spark within a cylindrical combustion chamber.

Spark plugs are made of a variety of materials. In the most common variants, copper, nickel, iridium, and platinum are utilized in varying amounts. Ceramics are used as insulators and protectants in spark plugs.

Now, how does it work? First, you need to learn about its components. If you want to watch a video to learn about how it works, you can check out this video on YouTube:

The ignition coil, which sends a high voltage to the terminal and ranges from 20,000 to 40,000 volts, is located at the top of the spark plug. Also, the central electrode then serves as a conduit for the voltage to be delivered.

Its innermost area would be a fragment of copper to conduct electricity down to the insulator tip or the spark plug nose. There will be a gap between the central and ground electrodes at the very end.

The electrode gap is the name given to this area. In order to generate a spark, a bigger gap between the center and ground electrodes would necessitate a higher voltage.

In addition, the other parts include the screw thread, which allows the spark plug to be screwed into the engine, and a hex nut to tighten the spark plug. This part is also grounded in the engine. You may also observe a white area.

The porcelain insulator is what you’re looking at. This component keeps voltage from leaking out of the top along the central electrode.

Signs You Need To Change Your Spark Plug

Drivers and mechanics often believe that if their car won’t start, it’s because of a battery problem. While this is absolutely a possibility, it isn’t the only one.

It could be a problem with worn-out or damaged spark plugs. These small spark plugs, after all, are in charge of a lot. You can tell when to change your spark plugs by looking for these warning signals.

Check Engine Light Flashes

The check engine light might be caused by faulty spark plugs, coil packs, or spark plug wires. If a plug starts to fail in a modern car, a flashing check engine light would be the most apparent event.

According to professional technicians, a flashing engine light could indicate the occurrence of potentially catastrophic misfires.

A misfiring engine indicates that one or more spark plugs aren’t firing properly. This might produce a stuttering sound or feel like a power outage or strong shaking.

Poor vehicle performance, low fuel efficiency, greater exhaust emissions, rough idling, and a broken catalytic converter are possible consequences of persistent misfiring.

According to most manufacturers’ recommendations, spark plugs should be replaced as routine maintenance.

Driving with misfiring spark plugs can place unnecessary stress on your vehicle’s catalytic converter (the engine’s exhaust cleaner), which can result in pricey repairs.

In addition, abrasive idling, uneven power accelerating, and increased exhaust fumes are signs of misfiring spark plugs.

Car Has Trouble Starting

The spark plugs in your engine are crucial in generating the spark that runs it. However, spark plugs that are old and worn out have difficulty fulfilling their intended job.

If your automobile stalls when you start it, it could be a spark plug problem or damaged wires. And if your automobile has no power and won’t start, the battery is most likely to blame.

Increased Fuel Consumption

Your gas mileage will suffer if your spark plugs are on the brink of failure. Worn spark plugs won’t efficiently combust the fuel that goes into the engine, so your vehicle’s fuel consumption will increase, costing you more money at the pump.

If you’re getting less mileage for every tank of gas, you may have rusted or corroded spark plugs.

The area between plug electrodes can expand or contract as spark plugs age. Causing them not to fire consistently, wasting fuel, and raising pollutants.

Generally, a defective spark plug can reduce fuel efficiency by 30%.

Idling Engine

Keep an ear out for rattling, pinging, or knocking sounds, which are all signs of a damaged spark plug.

Your vehicle’s spark plugs may not be working correctly to keep the engine going if it makes any strange sounds or sensations while idling.

Poor Acceleration

When pressing down on the accelerator pedal, you may have a spark plug problem if it doesn’t respond as it should.

The problem could also be triggered by other issues such as dirty fuel injectors, defective oxygen sensors, or a faulty fuel pump.

Have your car inspected by a trained mechanic before you go out and buy new spark plugs.

It Is Way Over Advised Changing Period

When it comes to car maintenance, it’s always preferable to stick to the manufacturer’s schedule. Consult your vehicle’s recommended maintenance plan to determine when your spark plugs should be replaced.

Spark plugs, fortunately, do not wear out quickly. After 80,000 miles, they are usually replaced after a certain time.

If you are experiencing these problems, you should have your engine tuned up and your spark plugs checked.

Don’t put off replacing your spark plugs if they’re worn or broken because it could damage your engine. Consult a highly experienced mechanic to have your car inspected.

How Long Does It Take To Change Spark Plugs?

You can watch this YouTube video on spark plug replacement if you want a quick and easy guide to follow along with:

This video will cover how to replace your spark plugs within your car or truck, covering all the essentials you will need.

Starting from knowing when you need to change your spark plugs, the best one for your engine, what tools you will use, how to gap it properly, and a few tips to easily remove your spark plugs and wires.

The video will also cover the installation process, like when to use anti-seize and dielectric grease to guide you safely.

You’re ready to replace your spark plugs now that you’ve figured out what it does and what warning indicators to look for. To assist you in this procedure, a few steps are listed below.

What You’ll Need

Before you start, you’re going to need some tools and materials. Here’s what you will be using.

• Gap gauge
• Needle-nose pliers
• Rags
• Socket/ratchet set
• Spark plug wire puller
• Swivel socket
• Torque wrench
• Anti-seize compound
• Dielectric grease
• Spark plugs

7 Step Procedure On Spark Plug Changing

1. Initiate With An Inspection

As a result of normal use, all spark plugs will darken slightly, turning black or brown, but keep an eye out for carbon build-up, oil, or gasoline on the plug.

A more thorough examination may be required if any of these signs are present.

Take a look at the middle electrode. If it’s still nice and proportional, it might not need to be replaced.

However, regardless of how the plug appears, replace it within the specified service time because spark plugs are inexpensive and crucial to a car’s health.

Use the gap gauge to verify the spark plug gap if you decide to keep it. Examine the manual for any gaps that need to be filled in and make the required revisions.

Don’t use a hammer or beat it against a hard surface when closing the distance. Tap it lightly with a hand or a towel over it and tap it on a hard surface to loosen it up.

2. Open Up Your Hood And Clean Up

Begin by removing the air filter assembly and the top of the engine’s plastic “vanity” cover (when in use).

Vacuum hoses should be tagged to be returned to their proper location. Learn how to remove the top of a four-cylinder engine or the banks on a “V” engine before moving to other sections.

To keep debris out of the cylinders, blow compressed air around the ignition coils. Then, before prepping your tools and new plugs, blow any leftover loose dirt from the engine.

3. Remove The Ignition Coil

Pull up on the locking tab to disconnect the ignition coil electrical connector. Then remove the connector from the coil by rocking it back and forth. Pull out the entire coil and boot assembly by removing the coil hold-down bolt.

Some COP systems come with a spring and rubber boot that can be removed. Use needle-nose pliers to remove them and replace them with fresh pieces if they don’t come out with the coil. Remove the old spark plug after that.

The spark plug wire will finish in a boot that attaches to the spark plug if your automobile does not have COP ignition. You can easily remove the boot with the help of a spark plug wire puller.

4. Unscrew Your Spark Plug and Boot

Check to see if the engine has cooled down. To disconnect the spark plugs, use a spark plug socket. Follow these instructions to avoid thread damage.

Remove debris from COP applications by blowing air down into the spark plug well.  

Then, loosen the spark plug about a half-turn counter-clockwise and apply a small amount of penetrant fluid into the base/thread area. Allow for soaking for a few minutes.

The manufacturer may provide additional removal steps for some engines. Look at the repair manual.

Take note of whether there is a lot of resistance when you turn the spark plug counter-clockwise. If you run into resistance, slowly turn the spark plug clockwise and back and forth.

If the plug refuses to unscrew, you should seek professional assistance. Depending on your car, repairing damaged cylinder head threads can be costly.

5. Gap Your Spark Plug

Before installing a spark plug, make sure the gap is correct. Slide the appropriate wire gauge (or gap gauge) between the electrodes. Between them, the wire should dangle slightly.

If the gap is too tiny, pry it open using the gap gauge. And then, you want to tap the side electrode lightly on a firm surface if the gap is too large.

Thread the plug by hand into the cylinder head after applying a small dab of anti-seize compound to the threads.

6. Lube Up And Install Your New Spark Plug

In today’s engines, it’s important to get the proper torque on a spark plug.  Always use a torque wrench and the spark plug torque standards recommended by the manufacturer.

Insufficient torque can cause a plug to blast out of the cylinder head, destroying the threads in the process. The plug will be distorted if there is too much torque applied.

Reduce torque by 10% if you put the anti-seize compound on the plug threads. If you don’t have a torque wrench, look up manual tightening procedures and spark plug torque standards on the spark plug manufacturer’s website.

7. Lube Your Spark Plug Boot Before Reassembly

Before reinstalling the coil, apply a tiny layer of dielectric grease to the inside of the spark plug boot. The lubrication helps minimize misfires and makes removing the boot easier in the future.

Replace the ignition coil, hold-down bolt, the electrical connector for the coil, air cleaner, and the vanity cover, then turn it on. Remember, the technique is the same for non-COP ignition system boots.

Frequently Asked Questions (FAQs):

If you have any specific questions, you might find the answer here in the FAQs.

Is It Easy To Change Spark Plugs?

Just like changing tires or oil, replacing spark plugs is a simple and inexpensive task that could be done from your home.

Although they do not require much maintenance, spark plugs are just as crucial and must be examined regularly.

How Often Do You Need To Change Spark Plugs?

Furthermore, experts and manufacturers agree that you should replace spark plugs every 30,000 miles, consistent with most manufacturer recommendations.

Is Replacing Spark Plugs Expensive?

Whether you go to a mechanic or do it yourself, replacing spark plugs can cost anywhere from $66 to $250. There is a possibility that you will require additional repairs or maintenance.

Should I Replace All Spark Plugs At Once?

Yes, replacing all plugs at once is the most effective approach to maintaining constant performance levels.

What Happens If You Don’t Replace Your Spark Plugs?

If spark plugs are not replaced, they will deteriorate over time, resulting in a range of engine difficulties.

When the spark plugs fail to produce an adequate spark, the combustion of the air/fuel mixture is incomplete, resulting in a loss of engine power and, in the worst-case scenario, the engine failing to start.

The Takeaway

Most cars now provide “extended-life” spark plugs as standard equipment. They’re only a few dollars more than a standard plug, and they sound amazing to the consumer.

The service life of extended-life spark plugs is commonly rated at 100,000 miles. As these plugs get closer to the end of their useful lives, the gap between the two leads grows, reducing efficiency and increasing the risk of misfiring.

If your spark plug erodes to the point of breaking, it could cause serious damage to the interior of your engine cylinder, demanding a costly replacement.

Check the owner’s manual for your car to determine how long your spark plugs are rated for. Never exceed the rated mileage of your spark plugs.