How To Use Spark Plug Boot Protector?

How To Use Spark Plug Boot Protector

A damaged spark plug can lead to misfires, electrical leakage, and potentially a damaged engine. Therefore, it is good practice to check an engine’s spark plugs periodically. Using spark plug boot protectors is one of the ways you can maintain the plugs well to make sure engine performance isn’t compromised.

If you were looking at how to use spark plug boot protector, look no further as we have you covered with our well-detailed and easy guide!

What You Should Know Before Getting Started

There’re two ways you can protect the boot; using dielectric grease and using a heat shield. While both methods have simple procedures, using dielectric grease is much easier than the latter.

1. Dielectric Grease

This type of grease is also known as tune-up grease. It is a viscous non-conductive substance mainly used to prevent electrical shorts or leakages between electrical connections. It also protects metal parts from dirt and corrosion. Made with a silicon base and thickener, they generally have a grayish milky color.

They can also be used as spark plug boot protector grease. Some benefits of using dielectric grease are –

  • Prevents voltage leaking
  • Protects against dirt, corrosion, and water damage
  • Reduces electrical overheating
  • It cuts down material bonding
  • Useful for insulating electrical connections in a very cold environment

2. Heat Shield Boot Protectors

Spark plug boots are used to insulate the connection of the spark plugs with the ignition wire. Although factory plug boots can do the job, they are not best suited for high-performance engines as they can melt down with overheating. The heat shield boot protectors can protect wires from heating and arcing.

How to Apply Spark Plug Boot Protector Grease

Applying dielectric grease on a spark plug boot protector is the easiest way to add a safety layer to spark plugs. To apply grease on a plug boot protector, follow these steps –

  1. Shut down the engine, and open the hood
  2. Take off a spark plug boot
  3. Clean residual carbon from the boot and the spark plug
  4. Take a small amount of dielectric grease on a cotton bud or a similarly sized tipped tool
  5. Apply a thin coating of the grease on the inner wall of the plug boot
  6. Rub off extra grease around the open end of the boot
  7. Put it back in the engine with the spark plug

Dielectric grease can be used as a spark plug grease substitute. Using excess grease should not cause any damage, but you better not apply it too much.

How to Use Spark Plug Boot Protector Heat Shield

Heat shields for spark plug boots usually come in two options; 90-degree spark plug boot protectors made of metal and boot protectors that are made from flexible materials.

A metal heat shield will fit on top of the spark plug boot, whereas the flexible ones have to be slid around the spark plug boot.

However, your hand may get dirty and oily during the process, so you may wish to keep a towel nearby.


What’s the difference between dielectric grease and lubricating grease?

Dielectric grease is made from a silicone base and thickener, while lubricating grease is made from lubricating oil and other additives. Both are used for different purposes. Dielectric grease is used between electric connections to prevent voltage leaking, damage from water and moisture, rubber gaskets cracking, etc.

Is Vaseline a dielectric grease?

No, Vaseline is a petroleum jelly formulated from waxes and minerals, whereas dielectric grease is made from a silicone base and thickener. It should be noted that using Vaseline instead of dielectric grease may cause permanent damage to the component where it is being applied.

Does spark plug boot need grease?

It is not required to use grease in spark plug boots. But, using it can help enhance the spark plugs’ longevity and performance.

What happens if you use too much dielectric grease?

Although it does not cause any damage directly, using excess dielectric grease in spark plug boots will make it difficult or impossible for the plugs to fit inside them.


Using a spark plug boot protector is an inexpensive and easy way to enhance your vehicle’s ignition system. It ensures improved performance and longevity of the spark plugs. With all that being said, you should now have a clear idea about these protectors.

2 thoughts on “How To Use Spark Plug Boot Protector?”

    1. It is not recommended to use boot protectors on spark plugs or in spark plug threads. However, using those protectors may seem effective for a while. But in the long run, there are chances of overheating, leading to unwanted events as spark plugs deal with excessive heat sometimes.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top