What Causes Spark Plugs To Go Bad Fast? (10 Factors)

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You find yourself changing your car spark plugs every now and then, and you’re worried as to why this is happening, and you wish to know what causes spark plugs to go bad fast.

Well, what makes spark plugs go bad fast is partly due to the gap between the electrodes wearing down over time and there not being enough voltage at the plug tip for a good ionization charge.

But that’s not all; there are other things that could make your spark plugs to be failing more often than required, and we’re going to talk about that in today’s post.

But first, let’s get to understand what spark plug is in the first place!

What Are Spark Plugs?

Spark plugs are a small metal piece that sits inside the engine of a car and emits an electric current. This allows the car’s fuel to combust with oxygen in order to produce energy for driving power.

The spark plug is responsible for making sure gasoline ignites and runs through the air intake manifold, which leads up into each cylinder of your vehicle’s engine.

This process is called the spark ignition cycle, and it happens every time you turn your car on.

In order to work properly, your vehicle’s spark plugs need a good connection with the distributor cap and coil after they have been installed in an oxygen-free electric environment for 15 minutes or more before installation of new spark plugs.

When these two components are not connected, the spark plug can push hot gas from a cylinder and it will cause a misfire in your engine.

If this happens often enough, you may need to replace your car’s spark plugs with new ones – or even re-wire them into the distributor cap for more effective connections.

What Happens When Spark Plugs Go Bad?

What Causes Spark Plugs To Go Bad Fast

When a spark plug fails or starts breaking down is when problems occur in other areas of the engine. Often times, you will notice a misfire in the vehicle or it may be difficult to start up.

As a car owner, it’s important to identify when these components need replacement, as they can cause serious damage if left unattended.

What Causes Spark Plugs To Go Bad Fast?

There are a few things that can make a spark plug to go bad fast, some of which include:

1. Build of oil and carbon

The most common cause of a spark plugs to go bad is due to the buildup of oil, carbon and combustion byproducts.

Spark plugs are designed with an anti-corrosion coating that helps protect against elements in the engine from damaging them over time. This also includes some types of contaminants like lead or copper particles from worn valve seats.

However, these coatings are not impervious and they will eventually wear down and crack from the buildup of oil, carbon and combustion byproducts.

2. Use of leaded gasoline

The use of leaded gasoline is another common cause of a spark plug to go bad as it can introduce lead into the engine which then deposits on components like valves or piston rings. This lead buildup will then work its way into the spark plug.

3. Poor fuel quality

Poor fuel quality can cause spark plugs to go bad quickly. This is because the material inside of a poor-quality fuel filter does not last as long, and it has more contaminants in it which will then enter into your engine through both the intake manifold from when you are idling and the exhaust system when you are running.

When this bad fuel quality gets into your engine, it will cause more wear on the inside of a spark plug and can even start to erode off some of the insulators as well.

This in turn creates electrical shorts that start throwing sparks everywhere instead of just where they need to be for ignition.

This will not only cause a misfire, but it can also throw off the timing of your engine which is bad for performance and gas mileage.

4 Bad fuel filters

Bad fuel filters can also be the main culprit behind spark plug going bad fast.  The fuel filter acts as a protective barrier for the engine and cleans it of dirt, rust particles, and other contaminants.

When your vehicle’s air intake system is exposed to too much dirt or foreign materials in the gas, this can affect your spark plugs performance.

When you have enough exposure to bad quality fuel filters, there might be instances that even the spark plug will go bad fast.

5. Loose wire connection

The causes of spark plug failure are often due to a loose wire connection, low-quality plugs or even improper engine tuning.

It is important that you keep your car tuned up and check the soundness of all wires before replacing any parts related to spark plugs. In addition, make sure you only use high-quality spark plugs to avoid any issues with premature wear.

6. Overheating

Basically, overheating of the spark plug’s tip can cause it to wear out prematurely. There are several things that can cause this.

For example, if the engine timing is off and pre-ignition happens, this can result in excess heat buildup in the combustion chamber, which will consequently affect the spark plug.

7. Inappropriate spark plugs gap

The metals on the tip have a small gap, which must be measured accurately for your engine when the spark plug is installed.

Now, if the gap is not correct, extra stress can occur on the tip, leading to wear out faster. This is arguably one of the reasons the spark plugs might go bad fast.

8. Leaky head gasket

Coolant leaking into the combustion chamber can also lead to spark plug fouling. This is basically a big problem because it can be insanely expensive to fix a leaky head gasket.

A fouled spark plug may be an indication that a head gasket is beginning to leak and should be fixed immediately.

9. Type of engine oil

The type and condition of the engine oil. A good quality synthetic engine oil can increase the lifespan of a spark plug by 10%.

10. Paying no attention to your spark plugs

Spark plugs also need to be replaced if they are too old. The lifespan of a sparkplug can vary depending on driving conditions and engine make, but it’s generally safe to change them after every 30,000 miles or three years (whichever comes first).

It is important to remember that spark plugs are not meant to be replaced for the sake of it, but if you notice any signs of wear or degradation, then it is time to change them.

The two most important factors in deciding how long a spark plug lasts before they need replacing are:

  • The quality and condition of your fuel. If you use high-octane gasoline, you will get about three months more out of your spark plugs before they need replacing.
  • The type and condition of the engine oil. A good quality synthetic engine oil can increase the lifespan of a spark plug by ten per cent.

Additionally, if there is too much air or fuel in your engine it could cause increased cylinder pressure, which will make the electrodes to wear quicker.

If you are running your car at an altitude of over a mile above sea level- for example on “The Pikes Peak” in Colorado – it can also cause spark plugs to go faster and sooner than planned as their voltage cannot be controlled by atmospheric changes, such as air density.

How to Prevent Spark Plug Failure

Below are the precautional measures you should take to prevent your spark plugs from going bad fast:

  • Keep engine tuned properly. This can help avoid the need to replace plugs and wires prematurely.
  • Change spark plugs every 30,000 miles or less as needed for your type of vehicle. A loose wire connection usually causes a misfire which could lead to plugged up spark plug holes in the head that will cause hot spots on the platinum.
  • Use a set of spark plugs that are designed for your engine. Using low quality plugs will wear out more quickly, so make sure you buy high grade ones.
  • Disconnect the negative battery cable and wait at least 30 minutes before doing any work on the vehicle to eliminate power shocks from damaging computer components like ECUs or other wiring.

Frequently Asked Questions

How often should I change my spark plugs?

Spark plugs typically need to be replaced every 20,000 miles. Some manufacturers recommend changing them at 30,000 miles or 45,000 kilometers.

There can also be a physical warning that your spark plug needs replacement soon: It gets too hot and blows out the insulation coating on the wire, which causes a short.

Also, when you check the spark plugs on your car, make sure to check for Physical Damage. Check that there are no physical signs of damage such as cracks or missing pieces in the electrodes. You may need to replace them if they show any damage.

How fast can spark plugs go bad?

You can basically get up to 80,000 miles on spark plugs before they need replacement. But if you notice any of the signs mentioned earlier, it’s time to check out your spark plugs.

Can spark plugs suddenly go bad?

Yes, a good spark plug can just go bad and stop producing a spark all of a sudden.

How do I know if my spark plugs need changing?

There are a few signs that will tell you that your spark plugs need changing, such as if there’s misfiring, rough idle, or hesitation in acceleration, the car is hard to start, the ‘check engine light is on, your engine is really loud, etc.

What is the longest lasting spark plug?

NGK 6619 Iridium IX Spark Plugs has been proven to be one of the longest-lasting spark plugs. It offers the best mix of dependability, fuel efficiency, durability, and high performance.

These spark plugs feature an iridium construction – and provide a much longer lifespan than platinum and copper spark plugs.

Do spark plugs smell when going bad?

Yes, spark plugs usually produce a foul smell from the exhaust when going bad. Whenever there’s incomplete combustion, raw fuel will likely enter the exhaust, resulting in a smell similar to rotten eggs or sulfur.

This can be an indication that a spark plug isn’t working properly.

Can I drive with a missing spark plug?

As you already know, bad spark plugs can cause an engine misfire or an imbalanced air/fuel mixture. It’s very dangerous to drive with a misfire as it can damage your engine.


Hopefully, you already know what causes spark plugs to go bad fast as we’ve already outlined all the possible causes in this post.

If you are experiencing spark plugs going bad quickly or are having some other type of troubleshooting issue with your car, be sure to schedule an appointment with your auto mechanic.

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