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6 Tools Needed To Change Spark Plugs (+Should You DIY?)

January 3, 2022

Spark plugs are a relatively tiny part of the engine, and you need to be very careful when replacing a failing spark plug. 

So, what are the tools needed to change spark plugs?
Are any special materials required? 

In this article, we’ll answer these questions for you. 
We’ll also examine whether it is safe to DIY your spark plug replacement

This Article Contains:

Let’s get started! 

6 Tools Needed To Change Spark Plugs

Here are the six important tools you should have when changing spark plugs, and why: 

1. Spark Plug Swivel Socket With Extension 

To remove old spark plugs, you need a socket wrench that can twist the spark plugs inside the engine. An old plug can be tricky to get out sometimes, so you need an extension for your spark plug socket.  

A standard 5/8″ or 13/16″ socket wrench works for most old spark plugs. 

But if you can’t find that, get a spark plug swivel socket, which can fit into tight spaces and lock in so you can get an easy spark plug replacement. This spark plug socket set is ideal for plugs with a rubber insert and can handle delicate spark plug threads.

Note: Before removing the old spark plug, remember to blow compressed air around the ignition coil and spark plug. This prevents dirt and debris from getting into the plug hole.

2. Flexible Handle Ratchet

Modern engines often place their spark plugs in very tight and compact spaces. If a swivel socket doesn’t work, you can try using a handle ratchet.

You can even use a flexible handle ratchet to rotate the spark plugs in combination with a swivel socket wrench.

3. Spark Plug Boot Puller Pliers

The spark plug’s ‘boot’ connects the ignition coil to the spark plug in modern COP systems. The boot can get stuck to the old plug after a while. It is also surrounded by some spark plug wire, so you need to handle it delicately.

A bad spark plug boot can cause damage to the cylinder head and ignition coil. 

Boot puller pliers have a long tip that can gently pull the spark plug boot without damaging any spark plug wire.

4. Spark Plug Gap Gauge

The spark plug gap is very crucial to keep the plugs functioning, so you should definitely get a spark plug gap tool. 

When selecting a spark plug gap tool, you can either get a spark plug gap gauge, or a feeler gauge. 

The spark plug gauge helps to gap the plugs outwards or inwards to achieve the correct gap as per the specifications. 

All you need to do is insert the spark plug gap gauge between the center and ground electrodes. Then slide the spark plug gauge carefully towards the recommended specification mark on the gauge and adjust the electrodes accordingly. 

You can also use a feeler gauge for a more accurate spark plug gap estimate. Unlike a spark plug gauge, a feeler gauge can handle delicate metals like iridium spark plugs. 

5. Torque Wrench

A new spark plug needs to have proper torque in order to avoid engine damage and other problems. Overly tightening the plugs with the spark plug wrench can destroy the cylinder head, while loose plugs can just come off after a few uses. 

This is where a torque wrench comes in handy. You can refer to your manufacturer’s manual and tighten the new plug set using the spark plug wrench. 

6. Wire Loom Spacers

Wire loom spacers are meant to prevent arcing-to-ground and cross-firing in ignition systems that use a spark plug wire to carry the current. These help space the ignition wires and prevent misfires that can affect gas mileage, oil consumption, and engine performance. 

What Other Materials Are Needed For Changing Spark Plugs?

Apart from these tools, you will need a flat workspace in a well-ventilated area with plenty of light. 

You will also need compressed air and/or a vacuum to blow off any dirt or debris from the engine surface to prevent it from entering the spark plug hole. After that, you can safely replace your old spark plug. 

The following things may also be useful in the process: 

1. Anti-Seize Lubricant Or Dielectric Grease

An anti-seize lubricant or dielectric grease can prevent the spark plugs threads from permanently bonding to the cylinder head, spark plug boot, or surrounding wires. Just adding a drop or two to the spark plug threads helps!

Remember not to get the dielectric grease on the electrodes or the porcelain.

Note: You’ll most likely have to reduce the torque using a torque wrench when using dielectric grease. 

2. Spark Plug Wires

If you’ve been having problems with your spark plugs, there’s a high chance that your wires need changing too. Ignition wires can become brittle over time. They can break and cause misfires and problems with gas mileage. 

Remember to invest in quality ignition wires and coil pack sets to keep the system running smoothly.

3. Distributor Cap And Rotor 

With aged spark plug systems, the carbon tip at the base of the distributor’s center electrode can interrupt the electric flow from the ignition coil to the surrounding individual spark plug electrodes. 

The centrifugal force can also expel the ground-up carbon towards the inside of the cap creating what’s called “carbon tracking”. This then results in engine misfires and damage.

One very inexpensive way to avoid that and maintain maximum engine efficiency is to replace the distributor cap! 

Most mechanics suggest replacing the cap and distributor rotor as a pair. 

Doing so will ensure that the carbon button will properly mate with the new spring surface of the rotor. The new distributor rotor will also be free of erosion and transfer the spark with minimum resistance to the new plug. 

Spark Plug Replacement: To DIY Or Not To DIY?

A spark plug replacement can be intimidating if you’re not used to handling your car repairs on your own. A failing plug that is mishandled or incorrectly handled can cause engine misfires, damage, and catalytic converter failure. 

If you’re someone with decent mechanical knowledge, it should be okay to change the old spark plugs on your own. If not, your safest bet is to reach out to professionals. 

Why not try RepairSmith?

RepairSmith is a mobile auto repair and maintenance solution with competitive pricing and a 12-month, 12,000-mile warranty on all repairs. To top it off, all your repairs are done by top-notch certified mechanics.

Fill out this form to get a cost estimate for spark plug replacement today!

Final Thoughts 

When it’s time to replace your old plug set, you need to be prepared with the appropriate tools. 

Replacing a failing spark plug can be pretty easy with the right tools and good mechanical knowledge. Remember to always refer to your manufacturer’s manual for details, and you should be good to go. 

But in case you find it too tricky, you can always reach out to your mechanic. Remember, incorrectly installing a new spark plug can affect your engine performance and interfere with the ignition system. 

Let RepairSmith help you.
Contact us today to book an appointment for your vehicle.