How to Deal With a Seized Spark Plug: Tips, Causes, and More

Your daily driver is made up of thousands of parts, with many of them are so small that you barely notice them at a glance. The thing about these small parts is that they can often cause big problems if left unaddressed, especially if the concerned part is the spark plug.

A Thing or Two About Spark Plugs

Spark plugs are small components that play a big part in the fuel combustion process. They’re generally made from ceramic insulators inside a steel shell with threads creating a gas-tight seal with the cylinder head.

Spark plugs produce the spark that ignites the air-fuel mixture. They create an arc of electricity across two leads without touching but close enough to jump the gap between them.

There are typically three types of spark plugs: resistor, platinum, and iridium.

Resistor Spark Plugs

Resistor spark plugs have a resistor in the center of the electrode, reducing electromagnetic noise and radiation from the ignition system.

These resistors are usually between 2,500 and 7,500 ohms.

Platinum Spark Plugs

Platinum spark plugs have a small amount of platinum on their electrode. Unlike conventional nickel alloy spark plugs, platinum spark plugs don’t react to oxygen, so they won’t erode as fast.

Iridium Spark Plugs

Iridium spark plugs have a small amount of iridium welded onto the tip of the center electrode. The small amount of iridium helps reduce the amount of voltage required to jump the gap between the center and side electrode.

What Causes a Spark Plug to Seize?

Spark plugs get very hot in the normal course of the work they do, and the washer or bevel seat on the spark plug must be in good contact with the head to carry the heat out of the plug.

Aluminum heads are more prone to have seized plugs than cast iron heads because of the different expansion rates of steel and aluminum. Some instructors (for mechanics) teach that engines with aluminum heads should be allowed to cool before removing the plugs, but most mechanics just remove them anyway.

Aluminum heads are more prone to have seized plugs than cast iron heads because of the different expansion rates of steel and aluminum.

– Richard McCuistian, ASE Certified Master Automobile Technician

How to Remove Seized Spark Plugs

A steady hand and sufficient knowledge of auto repair are crucial when removing seized spark plugs. If you’re not well-versed in handling this kind of issue, it’s best to leave it in the hands of a trained professional.

Diving into the complexity of this repair without the right tools and information can cause the spark plug to snap, leaving its pieces to drop into the cylinder. Once this happens, you won’t be able to drive your vehicle until all the pieces have been removed.

But if you’re confident enough to handle the task on your own, here are a few tips that might help.

• Move the piston to the bottom dead center and let the engine cool down.
• Use penetrating oil to soak the broken plug shell and wait for a few minutes.
• Use an easy out to tap into the plug shell head.
• Use a socket bar to apply counterclockwise pressure to remove the plug.

Anti-Seize for Spark Plugs: Yay or Nay?

Applying anti-seize on spark plugs is usually one thing that drivers consider doing to reduce the risk of having a seized spark plug.

Anti-seize compounds usually come in the form of a paste, grease, or coating with copper or nickel additives. They’re intended to prevent galling, seizing, and corrosion on bolts, flanges, and other metal components that are often exposed to high-temperature environments.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Typically using some light penetrating oil like PB Blaster will do the trick when installing new plugs, but usually this isn’t even necessary. Apply a small amount to the spark plug threads before screwing the plug in. Don’t use motor oil because it will actually cause the spark plug to be very difficult to remove.

Copper-Based Anti-Seize Compounds

Copper-based anti-seize lubricants are made with rust and corrosion inhibitors and antioxidants, making them resistant to saltwater and galvanic corrosion.

This type is mostly used on car parts like brake caliper bleed plugs, conveyor bushings, and gears.

Nickel-Based Anti-Seize Compounds

Nickel-based anti-seize compounds are highly resistant to acidic, caustic, corrosive, and extreme temperature environments.

This type of lubricant is generally used on furnaces, high-pressure flange bolts, and crane gears, among others.

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Should You Put Anti-Seize on Spark Plugs?

Anti-seize manufacturers mean well, but using such lubricant can actually damage your spark plugs, according to experts.

Spark plugs are usually pretreated with anti-seize additives before they roll out of the factory. Adding some more can lead to complications in the long run.

Spark Plug Service

If one of your spark plugs is seized, then there’s no other option but to replace it. Here are a few tips on how to successfully replace a bad spark plug.

Tip #1: Always check the service information concerning your spark plugs. Make sure to follow manufacturer-specific instructions and check for technical service bulletins (TSBs) that can affect the new spark plug.

Tip #2: Make sure that the engine has cooled down before removing the spark plugs, especially if your engine has an aluminum cylinder head.

Tip #3: Remove dirt from the spark plug using compressed air or a brush to prevent cylinder contamination.

Tip #4: Check the spark plug gap and correct as needed. Also, make sure not to damage the tip on the center electrode.

Tip #5: Use a thread chaser to clean the threads and install the spark plugs by hand before using a plug socket and torque wrench to tighten them.

Get a Replacement Spark Plugs Without Leaving Your Home

It’s best to replace seized spark plugs as soon as possible if you want your engine to fire normally again. Because applying anti-seize on spark plugs is a bad idea, purchasing new spark plugs is the best course of action. Good thing you can easily find new spark plugs at CarParts.com.

Ordering from CarParts.com is a breeze. You don’t even need to leave the comforts of home to browse our catalog for replacement spark plugs. Our easy-to-navigate site comes with a range of filters that’ll let you view spark plugs within your budget, from your preferred aftermarket manufacturers as well as those that fit your vehicle. It only takes a few quick clicks to buy from our site using our secure and convenient checkout. From there, all you need to do is wait. We’ll ship the part straight to your door in as fast as two business days.

Get your vehicle’s engine back to peak condition. Buy replacement spark plugs at CarParts.com today.