What tool is best for removing spark plugs?

When it comes time to replace your vehicle’s spark plugs, having the right tool for the job can make the process much easier. Spark plug socket wrenches are specially designed tools that allow you to securely grip and unscrew the spark plug from the cylinder head. But with different styles and sizes of spark plug sockets available, how do you know which one is the best for removing spark plugs on your particular vehicle?

What Are Spark Plug Socket Wrenches?

Spark plug socket wrenches are tools made specifically for removing and installing spark plugs. They consist of a socket that grips the spark plug, an extender that provides added reach to access plugs deep in the engine, and a wrench or ratchet to turn the socket.

Here are the key features of spark plug socket wrenches:

• Hexagonal socket grips the spark plug’s hex base.
• Rubber insert inside the socket provides a tight grip and prevents slippage.
• Various socket depths to fit different plug designs.
• Extension bars of different lengths can be attached to improve access.
• Can be used with a ratchet, breaker bar or torque wrench.

Spark plug socket wrenches are designed to safely grip spark plugs so you can apply the needed force to loosen or tighten them without damaging the ceramic insulator. The rubber insert allows a solid hold while also providing enough cushioning to prevent cracking the plugs. The long extender gives the added reach you need to easily access plugs at the back of the engine.

Choosing the Right Spark Plug Socket Size

Spark plug sockets come in different sizes to fit the various spark plug designs used in vehicles. Here are some of the common spark plug socket sizes you’ll see:

• 13/16 inch – For older model vehicles with large, standard 14mm spark plugs.
• 5/8 inch – Fits many modern, compact 14mm plugs.
• 9/16 inch – For small, 10mm plugs used in many Japanese vehicles.
• 16mm and 18mm – For European vehicles using metric plugs.

The socket size needs to match the spark plug’s hex size in order to grip and turn it properly. If you use an incorrectly sized socket, it can round off the hex edges on the plug, making it very difficult to remove.

The best way to determine which size socket you need is to refer to your vehicle repair manual. The make, model and year will list the proper spark plug socket size for that engine. You can also remove a spark plug and physically measure its hex width with a metric ruler or caliper. This will clearly show which size socket is required. Auto parts stores also have sizing charts to look up your vehicle’s spark plug socket size.

Socket Depth Considerations

Along with the hex size, pay attention to the socket depth. Spark plug designs come in different lengths, from short compact plugs to longer projected tip plugs. The socket depth needs to be able to fit over the length of the plug so it can fully grip the hex base.

Shallow sockets are made for short traditional plugs, while deep sockets are required for longer extended tip plugs. Using a socket that’s too shallow can result in the wrench slipping off the plug. On the other hand, an overly deep socket may not allow you to thread the plug in far enough during installation.

Refer to your repair manual not just for the proper socket hex size but also the recommended depth. Sockets typically come in 3/8-inch, 5/8-inch and deep 3/4-inch depths to accommodate various plug lengths.

Other Spark Plug Socket Features

In addition to the right size and depth, here are some other helpful features to look for in a spark plug socket:

• Magnetic socket – The magnet helps hold the spark plug in place in the socket to prevent dropping it during removal/install.
• Rubber cushion – A rubber pad in the gripper provides a secure hold while minimizing damage.
• Knurling – Knurled grip on the exterior makes the wrench easier to turn by hand.
• Jointed extender – An extender that flexes in the middle improves access in confined engine spaces.
• Universal joint – Allows angling the wrench for getting at hard to reach plugs.

High quality spark plug sockets also tend to be very durable, often made from drop-forged chromoly steel that withstands years of use without rounding off or deforming.

Spark Plug Socket Set or Universal Socket?

When purchasing a spark plug socket, you’ll generally have two options:

• Dedicated spark plug socket set – Comes with a range of socket sizes and depths to fit various plugs.
• Universal spark plug socket – One adjustable socket fits a wide range of plug sizes.

A dedicated socket set gives you the exact right fit for your vehicle’s plugs. However it may come with unnecessary sizes if you only need to use it on one vehicle. A universal socket provides flexibility for working on many different vehicles with its adjustable grip range. But the fit may not be as precise and secure as a dedicated socket.

For most DIYers working only on their own personal vehicles, a dedicated plug socket set with their required size is probably the best option. Professional mechanics who work on many different vehicle makes and models may prefer a universal spark plug socket for flexibility.

Socket Extender Length

Spark plug socket wrenches come with varying extender bar lengths from around 2 inches up to 9 inches or more. The ideal extender length depends on your vehicle’s engine design and ease of access to the plugs.

On vehicles with plugs located deep within cramped engine compartments, a longer 6-9 inch extender provides the necessary reach. For easier to access plugs, a short 2-3 inch extender is sufficient.

Extenders also come in jointed or swivel designs to improve maneuverability in tight areas. Make sure to choose an extender length that allows you to comfortably access all the plugs in your vehicle’s engine.

Drive Tools for Spark Plug Sockets

Spark plug socket wrenches are designed to be used with standard 1/4-inch and 3/8-inch square drive tools including:

• Ratchets – Allow quick turns of the wrench to thread/unthread plugs.
• Breaker bars – Give extra leverage for initially loosening tight plugs.
• Torque wrenches – Tighten plugs to precise manufacturer torque specs.

Most automotive tool sets come with compatible ratchets and breaker bars. A torque wrench is highly recommended to avoid over or under tightening spark plugs during installation. Refer to your vehicle repair manual for the proper torque procedure and specs.

Spark Plug Socket Brand Recommendations

When shopping for a spark plug socket wrench, stick with major professional tool brands for the best quality and performance, including:

• Snap-on
• Matco
• Mac Tools
• SK Professional
• GearWrench
• OTC
• Sunex
• Lisle
• Ingersoll Rand

These manufacturers offer well-made spark plug tools often covered by lifetime warranties. While there are cheaper generic socket sets available, they tend to be lower quality and less durable under heavy use.

Key Steps for Removing Spark Plugs

Once you have the right spark plug socket wrench for your vehicle, here is the basic process for removing and replacing the spark plugs:

1. Disconnect the vehicle battery.
2. Clean the area around the spark plugs.
3. Remove ignition coils if equipped (one coil pack may service multiple plugs).
4. Fit the socket over the plug and attach the extender and drive tool.
5. Break loose the plug by turning counterclockwise (use a breaker bar if needed).
6. Once broken loose, finish unscrewing by hand or with a ratchet.
7. Carefully pull out the spark plug.
8. Check the plug condition – should be light brown color on insulator tip.
9. Gap new plugs as needed – refer to vehicle specs.
10. Thread in new plugs by hand until finger tight.
11. Torque plugs to vehicle spec – usually 15-30 ft-lbs.
12. Reinstall ignition coils and connect battery when finished.

Always follow the service procedures in your vehicle repair manual. Replacing spark plugs is usually straightforward with the right tools, but take care not to overtighten or cross-thread plugs during installation. Periodically check torque after driving to ensure plugs remain properly seated.

Common Mistakes When Removing Spark Plugs

While removing and installing spark plugs is typically an easy job, here are some mistakes to avoid:

• Using the wrong size socket – Can damage plug and make removal difficult.
• Forgetting to disconnect battery – Risks electrical shock or damage.
• Not cleaning area before service – Debris and dirt can fall into engine.
• Removing coils incorrectly – May damage expensive ignition coils.
• Using excessive force – Can break the ceramic insulator on plugs.
• Cross-threading new plugs – Results in poor fit and cylinder damage.
• Overtorquing plugs – Can distort cylinder head threads.
• Not torqueing to spec – Plugs may loosen leading to misfires.

Working carefully, using the proper tools, and following the procedures in your vehicle repair manual will minimize mistakes and ensure successful spark plug service.

Conclusion

Replacing spark plugs is a key part of regular maintenance to keep your vehicle’s engine running efficiently. Specialized spark plug socket wrenches make the removal and installation process much simpler. Choose quality dedicated or universal sockets in the proper hex size and depth. Combined with ratchets, breaker bars and torque wrenches, you’ll have the right tools for quick spark plug servicing.

Carefully follow the manufacturer procedures and use the recommended torque settings. With some basic mechanical skills and the right spark plug socket wrench, you can easily swap out worn plugs for fresh ones and be back on the road in no time.