Spark plugs play a massive role in a car’s performance and reliability, so it’s important to know things like… when to get new spark plugs, how expensive those new ones will be, and how to be on the lookout for signs of wear and tear.
Let’s learn more about spark plugs and how they function in your vehicle.
What Is The Function Of A Spark Plug?
Before anything else, we need to know what a spark plug does. To put it simply, the spark plug creates a spark to trigger the air and the fuel in the engine cylinders to generate combustion to engage the engine which leads to the start of the car.
Spark plugs have two primary jobs: first generating a spark to start the engine, secondly, keeping igniting sparks while the engine is working in between the combustion cycles. They are quite literally the “spark” you need to get your vehicle turned on and driving properly.
If the spark plug does not function correctly it will affect the performance of the engine operation, denigrate the fuel economy, and potentially hamper the accelerating power.
Do Electric Cars Have Spark Plugs?
If you own an electric car, you don’t need to worry about spark plugs. These vehicles use a battery to power their electric systems.
Spark Plug Advice From The Experts
How Often Should I Change My Spark Plugs?
Spark plugs are advised to be changed every 30,000 to 60,000 miles on average. This may differ depending on the type of plug.
There are two types of spark plugs, long-life plugs, and conventional plugs. Long-life plugs are usually platinum or iridium tipped thus they perform for a longer time. Long-life plugs needed to be changed every 60,000 to 150,000 miles, whereas conventional plugs should be changed every 30,000 to 50,000 miles.
Spark plug changes may depend on the type of the vehicle, model, and performance. For example, a high-performance car may need its sparks plugs changed more frequently than a normal performing car.
Sometimes spark plugs might be needed to be changed much earlier if it fails, has a problem, or worn-out.
Warning Signs To Look For If The Spark Plug Has Issues
There might be different signs of a spark plug failure or other issues. Here’s a visual breakdown of the 9 most common spark plug issues:
Sometimes if a plug is too old or worn-out it might give the engine a hard time to start, accelerating may take some time or give a rough start for the car.
Poor Gas Mileage
The gas mileage can get affected if the plugs are contaminated, worn out, or cold.
This sign appears when one of the spark plugs stops operating.
Engine misfire means, one of the four cylinders failed to fire if one cylinder fails that leads to the other three cylinders to do the work which is originally for four engines. Thus these three cylinders are taking the load of the failed to fire cylinder.
This will cause less powerful, shaky, and rough performance.
Ignition Coil Failure
Worn-out spark plugs can also be the cause of ignition coil failure. An ignition coil creates a high-voltage impulse to generate electrical sparks to start the engine. If the ignition coil fails, the car will give an indicator to check the engine.
Checking The Spark Plugs
Experts say we can check the spark plugs from time to time for damages, or if the car is giving signs of spark plug failure. Usually, people would check the spark plugs when there are signs of engine misfiring or rough accelerations, etc.
Experts say a spark plug’s condition can sometimes exactly tell us about the problem in that situation, so they suggest checking the spark plugs properly to find the root of the issue.
Spark Plugs In Tan Or Grey Color
If the spark plugs are not overheated, have a very low deposit of oil, are not clogged and the color of the plugs are grey or tan, this means that the engine is still in good condition even if the plugs are old.
Black Oily Deposits
If a spark plug is clogged with black oily deposits, this gives the sign that there is oil present in the combustion chamber.
This happens if the car uses oil in short trips but the engine does not get enough time to heat up in between oil changes. Oil leaks need to be addressed quickly by a mechanic before any damage occurs to the vehicle. Scheduling your appointment should happen as soon as you notice the leak.
Failure/Clog Of Only One Spark Plug
This indicates that only the cylinder with that spark plug has problems while the other cylinders do not have any issues as their spark plugs are fine.
This causes the engine to hang in between or run abruptly, or if the engine is still cold after starting, but everything becomes normal after a short drive. This is when spark plugs should be replaced immediately.
Melted Or Overheated Spark Plugs
This sign indicates that the cylinder is getting overheated.
The cause of this issue can be either because of over lean of the air-fuel mixture, detonation, or the cooling system is not working properly. This issue is needed to consult an expert.
Replacing Spark Plugs As A Set
Many have the question that if a spark plug is damaged does that mean all the plugs needed to be replaced? The answer to this question is, Yes.
The reason is that spark plugs always come in sets, and this for not keep a chance of any failure of any plug due to the difference between the spark plugs if they are changed individually.
When an ignition coil fails all the spark plugs are needed to be changed as a set along with the spark plug wires, they also need to be replaced to ensure a smooth operating system in the future.
Sometimes in old cars, spark plugs are regularly cleaned and adjusted from time to time but this is not needed for new cars, spark plugs are directly changed to a new set of plugs and wires.
Spark Plug Replacement As A Precaution
Replacing spark plugs earlier as a precaution depends on the performance of the car, the mileage the engine of the car is giving, and the type of spark plug your car has.
How Many Miles to Change Spark Plugs?
If a car has a conventional spark plug it is always recommended to change them before their mileage limitation is due. On the other hand, if the spark plugs are long-life iridium or platinum-tipped plug, which is said to give miles up to 100,000 to 150,000.
Sometimes service center technicians may offer to change the spark plugs when they reach 50,000 miles, even when the engine is running smoothly and there are no gas or fuel problems then this is very early to be replaced considering that they are long-life spark plugs.
Why Replace Spark Plugs?
Although it is stated by many that long-life spark plugs can last longer than their running miles period because they have durable electrodes, it may still fail if carbon is deposited in the electrodes and the ignition coil may fail also if the spark plugs run for a very long time then usual.
Whether you have high-performance spark plugs or not, it’s important to keep up with your vehicle’s recommended maintenance schedule to ensure enduring engine performance and functionality.
So it is advised to replace the long-life spark plugs when they are close to their miles due.
Prices Of Spark Plugs And Wires
Replacing spark plugs means buying a new set of spark plugs and wires, and if the car owner does not know how to change them, it will require a professional installation. Spark plugs come in two types thus their prices also vary, the prices of the plugs may depend on the type of the car sometimes too though this is very unlikely.
How Much Does a Spark Plug Cost?
A long-life spark plug may cost from 15 to 50 USD each, whereas conventional spark plugs are cheaper in comparison which costs 6 to 15 USD each.
When fresh spark plugs are installed by an experienced parts department, charges may be higher. It largely depends on the type of vehicle you drive and the ease of installation involved.
If the engine design is normal, replacing spark plugs will be easier thus they may charge from 50 to 120 USD, but if the engine is an uncommon one then their charges will change according to its difficulty, which may go from 250 to 400 USD.
When a spark plug service is necessary, don’t mess around. Get fresh spark plugs right away before the vehicle’s fuel economy or driving systems are affected. If pricing is an issue, shop around your local area to find the best service specials near you.
Benefits of Changing Spark Plugs
There are several obvious benefits to changing your spark plugs routinely.
The chief benefit of changing your spark plugs is to improve fuel efficiency. A misfiring spark plug can decrease your fuel efficiency by upwards of 30 percent.
Smoother Vehicle Starts
Starting your vehicle without any weird jerkiness is a nice advantage to new spark plugs. If you’ve been dealing with difficult starts, it’s probably time for new spark plugs.
From an EPA standpoint, newer spark plugs help vehicles maintain better carbon emissions.