How Long Does it Take to Change Spark Plugs?

Before you change your spark plugs, get ready! You need the right tools, such as a wrench and spark plug socket. Check your car’s owner manual for the spark plug type and gap. When you have the correct tools and know the process, you are set to start!

  • Gather the right tools: wrench and spark plug socket
  • Check your car’s owner’s manual for spark plug type and gap
  • Start the process!

Gather the necessary tools and supplies to Change Spark Plugs

Replacing your car’s spark plugs is an easy job that should take no more than an hour. Gather all the stuff you need before beginning. You’ll require a socket set with a spark plug socket, new spark plugs, sandpaper/emery cloth, pliers, shop towels, anti-seize lube, dielectric grease and optional tools like a breaker bar or impact wrench. Get all these items ready before starting on the spark plug change!

how to change spark plugs

Park your car on a level surface

Park your car on a level surface before you begin changing the spark plug. This will make sure the support jack works correctly. If you are on a soft surface, like grass, put wood underneath each wheel. This will stop the car from sinking and creating an uneven surface. Verify that the car is leveled. Then, you can start working on changing the spark plug.

Locate the Spark Plugs

Change spark plugs? Easy! Start by locating them. Usually found under the hood. Depending on your vehicle, follow spark plug wires from distributor cap to the spark plugs.

how long does it take to change spark plug

Before you start, get the right tools. Like a spark plug socket or adjustable wrench.

Remove the engine cover

Find the spark plug cover. It could be held on with clips or screws. Check your car manual if you’re not sure.

Take the cover off to access the spark plugs. Then, you are ready to replace them:

  • Remove the old spark plugs.
  • Install the new spark plugs.
  • Replace the spark plug cover.

Locate the spark plug wires

Once you get the engine cover off, it’s time to spot the spark plug wires. The spark plug wires are usually connected either to the distributor or an electronic control module. Find help in your owner’s manual or vehicle repair manual, or ask your auto shop.

Next, take the spark plug wire off its connection point. This usually involves taking off a small metal clip or a retaining nut that attaches the wire to the distributor or other engine parts. You’ll find several other wires in the same area – just remove the ones mentioned in your manual.

After disconnecting all wires, find and inspect each spark plug by following the wiring from each terminal until you reach its spark plug. Lay out each wire and its parts so you don’t get confused when installing:

  • Retaining nut
  • Metal clip
  • Electronic control module

Removing the Old Spark Plugs

Changing spark plugs in a car is essential. Step one: Take out the old spark plugs. This takes around thirty minutes. Doing it right is critical. Let’s take a closer look at getting rid of the old ones.

change spark plugs

Disconnect the spark plug wires

Start by disconnecting the spark plug wires. It can be tricky to get the right spot where it connects with the spark plug. Remember where each wire goes. Use a ratchet or wrench to take them off. Clean them if there is corrosion. Keep debris away from the engine.

When each wire is disconnected, set it aside and continue:

  • Disconnect the spark plug wires.
  • Use a ratchet or wrench to take them off.
  • Clean them if there is corrosion.
  • Keep debris away from the engine.
  • Set the wires aside and continue.

Unscrew the old spark plugs

Start by unscrewing the old spark plugs. You need good visibility and a quality plug wrench. A professional can do it in 20 minutes, but if it’s your first time, it may take longer.

Locate the spark plugs on the engine. Attach the plug wrench with the correct size socket and start unscrewing each one slowly. Note any sludge or oil residue – this is something to tell your auto service technician.

Once all the plugs are removed, inspect them with a flashlight or an inspection device. Most of the time, they’ll show signs of wear which means you need to replace them. Keep the old plugs as reference, to note any differences when installing new ones and to confirm any future car performance issues.

Installing the New Spark Plugs

Changing spark plugs is not hard, if you have the right stuff. It often needs around half an hour. But before that, the old ones must be taken away. That is easy but can take a while. So, how long does it take to fit the new ones?

Apply a light coating of anti-seize to the threads of the new spark plugs

It’s important to apply a light coating of anti-seize to the threads of new spark plugs. This helps protect against corrosion and seizure during installation. Anti-seize is a lubricating compound, made from aluminum and copper. It reduces friction when installing plugs into an engine’s cylinder head. The correct type and amount should be used. Too much or too little could damage the plug and possibly cause it to not thread in properly or even break off.

For most spark plug applications, a 2mm coating of anti-seize should be enough. Unscrew the cap on the tube and dip each new plug into it several times. This will provide enough lubrication without overdoing it. After applying the anti-seize, proceed with installing the spark plugs. Follow either vehicle manufacturer instructions or step-by-step instructions in your repair manual.

Screw in the new spark plugs

Remove old plugs and fit spark plug wire boots. Now, screw in the new spark plugs. Check the gap for your vehicle. Incorrect gap or wrong plugs can cause misfires or rough engine performance. Use a feeler gauge and a spark plug gap tool to adjust the gap. Connect the plug snugly. Use a socket with an extension bar to avoid over-tightening. Securely refit the lead boots on each spark plug before starting the engine. Sparks can jump directly to earth if there is a loose connection between the boot and connector.

  • Check the gap for your vehicle.
  • Use a feeler gauge and a spark plug gap tool to adjust the gap.
  • Connect the plug snugly.
  • Use a socket with an extension bar to avoid over-tightening.
  • Securely refit the lead boots on each spark plug before starting the engine.

Finishing Up

Swapping spark plugs may be an easy task, based on the vehicle and plug. Check that the old ones have been taken out, and the new ones are ready.

The last steps to change spark plugs include:

  • What is necessary to complete it?
  • How long does the process take?

Reconnect the spark plug wires

After switching the spark plugs, reconnect the spark plug wires in their proper order. Make sure all four connections are clean, no grease or oil. Replace any wires that are fouled or damaged. To reduce resistance, wipe the contacts with a dry cloth or paper towel.

Match the colors of the wires with the coil terminals, usually back-to-front or left-to-right firing sequence. Secure the wires tightly onto their terminals. Don’t overtighten, as it can damage both the coil and the new wire end.

After tightening, your vehicle is ready to start up again!

Replace the engine cover

Secure and tighten the spark plugs. Replace the engine cover. Make sure the clips and clasps match up. Realign if needed. Use a screwdriver or metal file for extra support.

Start the engine. Check for any knocks or rattles. If all is well, you’ve successfully replaced the spark plugs!

Start the engine and check for any issues

Position the spark plugs properly. Start the engine and check for problems. If it runs normally, close the hood. If there’s a change in sound or speed, check the plugs or wires. See if the plugs are seated correctly. Tighten them with around 15 to 20 psi. Don’t over-tighten – refer to the owner’s manual or talk to an auto specialist.

Frequently Asked Questions


Q: How long does it take to change spark plugs?

A: The amount of time it takes to change spark plugs depends on the type of spark plugs being used and the vehicle you are working on. Generally, it takes about an hour for most vehicles.