Can You Use Dielectric Grease On Spark Plugs? [Here’s The Right Answer]

Have you noticed your brake lights don’t work even after a replacement? Then do check the socket connectors, which might be corroded. Dielectric lubricant protects from this type of corrosion. 

Now you may ask, can you use dielectric grease on spark plugs? In this article I’ve presented what’s a dielectric lubricant and why should you use it. Also, I’ll help you to apply it properly.

Scroll down to know everything about dielectric lube and get the most out of it without causing any mishap to your vehicle.

What Is Dielectric Grease And Why Should You Use It?

Before you start using dielectric lube, it’s good to know what it is. That way you can use it right and avoid any mishap.

Dielectric grease, also known as silicone lubricant, is a water-resistant lube. It’s made by mixing silicone oil with a thickener. The silicone oil is mostly polydimethylsiloxane, abbreviated as PDMS. So, usually, it’s a translucent white sticky paste. 

Now, this grease is non-conductive and non-hardening. It will maintain this greasy paste-like consistency throughout its life. So, it stays this way and doesn’t get hard or setup. 

Bare metal will have a chemical reaction with the oxygen in the air, which we know as oxidization or corrosion. If you live in a moist or wet environment, oxidization can build up over time to be a problem in your car. It will decrease the voltage, causing lights to dim and other devices not to work properly. 

In extreme cases, overheating can happen as the current attempts to break through and cause the plastic to melt, shorts and sparks. And in the worst case, it might start a fire too! 

Silicone grease can help you combat with all these problems. It’s an insulator and helps prevent voltage leaks. So, in high voltage situation, this can help reduce voltage leakage, like in the engine’s ignition system. 

You can also use it in low voltage condition as it prevents the wiring from oxidation, inhibits corrosion & seals out contaminants such as salt & dirt.

It also helps the plastic and rubber portions of the connectors. The oils in the lubricant help reduce gassing off of the plastic’s oils. This, in turn, prevents the plastic from getting brittle. It also lubricates rubber fittings to let those seal better. And it’s easier to take the connector apart when it needs a replacement. 

Can You Use Dielectric Grease On Spark Plugs?

Yes, you absolutely can apply it. But how and where you use it can make a BIG difference.

Many of us wrongly assume that by applying silicone lubricant to wire terminals makes for a better electrical connection. And that’s a big no-no! Dielectric, the name itself, tells us it’s an insulator. So it shouldn’t be used directly on the mating surfaces of electrical joining like pins and sockets.

You should apply it on the rubber boots, where the spark plug meets the ignition coil to keep it protected from the moisture and leakage. 

You may also read
  1. Best Spark Plug Wires for 5.3 Silverado
  2. Best Spark Plug Wires For Chevy 350 With Headers

Should You Use Dielectric Grease On Spark Plugs?

Yes, you should. Here’s the reason why you should use the silicone dielectric lube on spark plugs and how it’s beneficial:

  • It helps the high voltage current to pass through the spark plug seamlessly.
  • Seals the rubber boot and prevents the passing spark from arcing around or go to ground through the boot.
  • Helps to keep the boots from bonding to the ceramic portion of the spark plug.
  • Prevents corrosion by keeping elements and moisture out of the spark plug boots.
  • If you don’t apply anti-seize lube, the boot will be infused to the plug. Using anti seize inside the boots make future removal much easier without tearing them.

Where Do You Put Dielectric Grease On Spark Plugs?

If you’re confused about how do you use dielectric grease on spark plug wires, here’s how to do it right:

Apply the silicone grease in a small amount in the inside of the spark plug boot. A cotton swab is a perfect applicator in this case. It will help you to spread it evenly. Apply a thin coat with a circular motion. Doing so will better ensure that the anti-seize covers the interior of the boot. Be careful not to put the lubricant on metal terminals. 

For extra protection, you can also apply a thin layer of lube to the ceramic insulator portion of the spark plug. Again, take care not to get any lubricant on to electrical conductors adjacent to it.

If you don’t have cotton swab, you can use your finger too. But make sure to wear gloves before doing so. 

What Happens When You Put Too Much Dielectric Grease On Spark Plugs?

Putting too much anti-seize can cause issues. As it’s an insulator, if the metals are in contact, the current won’t pass through. The spark can’t make it through a thick goopy film, and your ignition coils can’t function properly.  Your vehicle might not even start. In the worst case, it might cause a misfire.

So, use it sparingly and evenly, making sure that it won’t get inside the connectors.

Best Dielectric Grease for Spark Plugs

1. Permatex 22058 Dielectric Tune-Up Grease: Essential for modern high energy ignition system as it prevents voltage leaks and protects electrical connections and wiring from salt, dirt and corrosion.

2. Dielectric Grease/Silicone Paste/Waterproof Marine Grease: Great for many common tasks including changing spark plugs, lubricating brake caliper pins, lubricating and preserving rubber gaskets, O-rings, hoses, weatherstripping, etc., and fixing sluggish car windows. Also comes with an applicator brush.

3. Versachem 15309 Dielectric Spark Plug Boot Grease OEM: Specified waterproof, non-flammable, and corrosion-resistant dielectric lubricant. It works best on spark plugs, battery terminals, headlight sockets, electrical connections, etc.


Can I use dielectric grease on spark plugs threads?

The BRP manual recommends to anti-seize lubricant over the spark plug thread, but the NGK catalogue forbids to as they think over-tightening can occur. So, as long as you don’t over tighten it, there’s no issue using it. It helps to prevent possible seizure and seals the thread to keep the combustion gas inside the cylinder.

Can dielectric grease cause misfire?

There’s a lot of incidents that people experience misfiring in their vehicle after they change their spark plugs with dielectric lubricants. This could be due to too much application of the anti-seize. It might have insulated the connection and prevented the spark from travelling. So, apply it sparingly using a cotton swab. Better safe than sorry.

Can you use dielectric grease on spark plug boots?

Yes. You should use it to prevent arcing around the boots to the engine block. Again, it makes removal easier as the boot and the porcelain insulator tends to stick. Moreover, it also gives protection from corrosion. 


Is dielectric grease necessary for spark plugs? Yes, it is. Use it in the right way as we have mentioned. Doing so will make your vehicle fit and running well for a long time. Also, if you live in a moist place, apply it to the exteriors of the metal equipment. It will help for their seamless functionality and avoid corrosion. Just avoid the mating surface, and you are good to go.

More to explore
  1. How to tell if you Need New Spark Plugs
  2. Best spark plugs for chevy cruze 1.4 turbo
  3. Best Spark Plugs for f150 EcoBoost
  4. Best Spark Plugs for 4.7 Dodge Ram
  5. Best Spark Plugs for 5.7 Hemi