Are you having trouble starting your car and you think that the spark plugs have failed? So you decided to look into learning the spark plug replacement cost? Well, if this is the case, you are at the right place because there will be a lot to cover on this topic where we will learn everything when it comes to replacing these components.
Having a problem like this can be a really frustrating thing to deal with. But we know that it happens and this is why you need to learn everything when it comes to spark plugs. Now only the spark plug replacement cost. But everything when it comes to their work like the causes why they fail and the symptoms they produce.
Knowing this stuff will set you miles ahead of the competition and the people that are constantly ripped off by mechanics who accidentally misdiagnose some components and like in this case if the spark plugs are bad they will tell you that a coil is broken so you pay a whole fortune for the spark plug and coil replacement cost. This is why you need to understand these components and your car. And for that, we are going to help you out.
First, we are going to cover the basics of spark plugs and what they are in general terms. Then we will cover the causes of why they fail as well as the symptoms that they produce when they fail. After we will move to diagnosing the problem and covering the BMW spark plug replacement cost. Lastly, we will answer some common questions. So, if you want to learn more, follow along.
What Are Spark Plugs?
Now before we move on to more complex topics like the spark plug replacement cost. Let’s first focus more on the basics and learn what are spark plugs in general terms. Knowing this stuff will be extra helpful for you as a car owner to get yourself familiarized with these components if you want to replace them.
If you feel like you are better prepared, you can jump to the causes or symptoms. If not, keep up with us for a bit while we cover the introduction to the topic.
Spark plugs in simple terms are electrodes. They allow your car to start and drive off. But they are not only good for starting the car. Spark plugs also keep running until the engine runs. Meaning that they always have to be in perfect health if you want to have normal combustion.
If for some reason the spark plugs are malfunctioning. You will not be able to drive your car as you should and your car will suffer symptoms of bad spark plugs that we are going to cover later on.
But where these spark plugs are mounted? The spark plugs are mounted on the cylinder head. Meaning that wherever there is a cylinder head, there are spark plugs. On inline engines, there are between 3 and 6 spark plugs depending on how many cylinders the engine has. Meaning that each cylinder has at least one spark plug.
There are engines that are twin spark. Meaning that they have two spark plugs per cylinder like in the HEMI engines.
More spark plugs mean more expensive maintenance. Imagine that you have to replace 16 of them. It quickly adds up to the spark plug replacement cost. But how do these spark plugs work? Let’s see up next.
How Spark Plugs Work?
Now before we cover the symptoms of bad spark plugs and the spark plug replacement cost, let’s first see how these components work in practice, what makes them so special?
Spark plugs are also known as simple as plugs by many out there, they are components that transfer electric current to the cylinder.
Imagine that the piston is moving and compressing the gasoline inside of the cylinder. Then after the fuel is compressed, the spark plug is activating and releases an electric current. This electric current ignites the fuel and creates an explosion.
This energy then moves the piston in the opposite direction and spins the crankshaft. From the crankshaft, the energy is transferred to the transmission and then to the wheels.
Nevertheless, what is important for you is to know how these spark plugs work. They are basically electrodes that are installed in a metal housing that is threaded for you to be able to mount it onto the vehicle.
This electrode is insulated with the help of ceramic. This ceramic is the white thing that is on the spark plug. The ceramic can break so you have to be careful.
On the bottom part of the spark plug, you can see the electrode. While on the top you can see the connector. This is the place where the coil is connected to the spark plug.
The coil basically is an electric transformer that creates a strong electric current so the spark plug could ignite the fuel.
Overall, a very simple design that has been with us for decades and will be for many years to come. Now before we cover the spark replacement cost, let’s see what are the causes that can make the spark plugs fail.
Causes Why Spark Plugs Fail
Now as we got familiarized with how the spark plugs look and work, let’s focus on the causes why the spark plugs fail before we dive into the spark plug replacement cost.
Knowing the causes will tell you quite a bit when it comes to determining why your spark plug has failed and determining if you need to do a possible repair on your car if you don’t want this to happen in the future.
So, what are the different causes for this happening? Let’s elaborate.
1. Mileage And Age
The first and most basic cause why the spark plugs fail is two factors which are the mileage that the spark plugs have on them as well as their age.
This is extra useful for you to know before you learn the spark plug replacement cost. As you probably know, spark plugs are not changed quite often in normal conditions. Usually, they are replaced every 60,000 to 100,000 miles.
The replacement interval also depends on the engine itself. Some engines by design go through spark plugs easily and you will replace them every 35,000 miles or so. Especially the twin spark designs that when one spark is failing, the other one will be replaced as well. So, beware of this situation.
Also, age affects the spark plugs as well. Old spark plugs do not work well as new ones. The materials deteriorate and if your spark plugs are older than 10 years then you better replace them and pay the spark plug replacement cost if you don’t want to have any other problems in the near future.
2. Damage Caused By Events Happening In The Engine
Now before we cover the spark plug replacement cost, let’s take a look at the other causes that can make your spark plugs foul. And trust me, there are a lot of them.
As you probably know, if you have a problem with the combustion there will be different events that will happen inside the cylinder. And based on these things the spark plugs can foul in different ways.
Let’s say that your fuel to air mixture is rich. Meaning that there is more gasoline than air in the mix. This will soak the spark plug electrode in gas and the spark plug will smell like gas very badly once you remove it.
On the opposite, if the car is running lean. A situation when the car has too much air and too little fuel in the mix. This will cause blisters on the electrode of the spark plug and the electrode will get damaged.
If the car is burning oil, the spark plug electrode will be all blacked out. This is a clear sign that your car is burning oil along the black clouds of smoke from the rear.
There are also other conditions like damage to the electrode by foreign objects. Namely, a screw accidentally fell in the cylinder and damage occurred. Or the valves got bent and the piston pressed the electrode. Anything can happen.
This is why you should be aware of this stuff and try to sort it out as soon as possible by replacing them and paying the spark plug replacement cost. But more on that, we are going to cover in a bit after we finish with the symptoms of bad spark plugs.
Symptoms Of Bad Spark Plugs?
Now as we covered the causes for spark plug fouling and we saw that these spark plugs can fail for a number of different reasons. Let’s now focus more on the symptoms of bad spark plugs.
Knowing the symptoms will help you decide if you potentially have bad spark plugs and if your spark plugs need replacing. In this case, you will have to learn the spark plug replacement cost. But more on that later on. So, let’s dive into the different symptoms of bad spark plugs.
1. Trouble Starting The Car
Now before we cover the spark plug replacement cost, let’s learn more about the first symptom of bad spark plugs. Which is the symptom when you have trouble starting the car.
A car with bad spark plugs or coils will potentially have trouble starting. It will not be happy at all and will continuously crank for a while before it starts.
So, if you notice that your car cranks a lot before it starts, either you have a bad battery or possibly the spark plugs or coils are worn out. If the battery is bad then you will have to test it with a multimeter and see how many volts of power does it have.
If you deem the battery good, you need to check the coils with an OBD2 scanner and see if you get any codes from them. In case there are no codes, then the spark plugs are the ones that are causing all this trouble to you and prevent you from starting your car.
Fuel-related issues can also be the culprit. Namely, a bad fuel pump or a clogged fuel filter, so beware of these components as well when it comes to poor starting ability. Now before we cover the spark plug replacement cost, let’s move to the second symptom.
2. Engine Misfires
The second symptom of bad spark plugs that we are going to cover before we cover the spark plug replacement cost is the situation when you experience misfires.
Engine misfires are basically explosions that do not happen at the right time. Engine timing must be perfect, so if you have misfires, then these misfires can be caused by bad spark plugs.
The spark plugs simply do not work as they should and your engine will not going to like this. You will notice these ticks coming from the top of the valve covers.
From the exhaust, you will also notice pops and bangs whenever there are misfires occurring in your car. Now let’s move to the next symptom before we cover the spark plug replacement cost.
3. Rough Idle
The third in our list of symptoms that we are going to cover before we learn the spark plug replacement cost is the rough engine idle.
Whenever you have a misfire on some of your cylinders, you can expect the engine to idle extremely roughly. And I mean really rough.
You will notice how the RPMs fluctuate on the cluster and the car will not be happy with this type of work at all.
This is because some of the spark plugs have reached the end of their lifespan and are starting to give up on you. The worse the problem gets the worse the idle will be. So, beware of this and make sure that you get this problem nice and diagnosed. More on that in a bit after we cover the symptoms. And then the spark plug replacement cost.
4. Engine Low On Power
The fourth symptom that we would like to cover before we cover the spark plug replacement cost is the situation when the engine is low on power.
Let’s say that you run a small engine and one of the cylinders is misfiring or the spark plug doesn’t work at all. In this case, this cylinder does not make any power at all. Causing you a lot of trouble down the alley.
The engine will feel underpowered and you will have trouble accelerating the car and maintaining speed. It could even try to stall on you if the spark plugs are too worn out. So, beware of this situation and make sure that the spark plugs are in good condition. Pay the spark plug replacement cost and enjoy driving your car. But more on that in a bit.
5. Bad Fuel Mileage
And the last symptom in our list that we will cover is the bad fuel economy. Whenever the ignition doesn’t cut it the computer inside of the car will try to dump more fuel and air into the mix to improve the combustion inside of the engine.
When this happens, your fuel economy will decrease and you will see how there is no power created from the engine and that there is no fuel in the tank as well. The fuel economy will get worse from 5 to 10 mpg in extreme situations and this is not good.
But what does the spark plug replacement cost? We will get to that in a bit. Now let’s learn how we can diagnose the matter.
How To Diagnose & Replace Bad Spark Plugs?
Now before we cover the spark plug replacement cost, let’s take a look at how you can diagnose and replace spark plugs. This will be very handy for you if you want to do this work at home using common tools. So, how they are diagnosed?
In order to diagnose a spark plug, you will have to remove it. There is no way around it basically. So, if you plan on pulling this off at home, you better come prepared with a long socket that will fit the hole and the threads of the spark plug. Plug holes are really deep and you will need a longer key to get the spark plug out.
Of course, the first thing you will need to remove will be the ignition coil. These coils are basically held by two screws and come out very easily. Next, get your socket wrench and remove the plug.
Once the plug is removed, remove all the other plugs in the same fashion and place them in the same order that you removed them. This will give you a great perspective to determine which cylinders were misfiring and causing you trouble and what you can do to avoid possible situations like this in the future.
Then bolt on the new plugs and tighten them really nice, not too much though. Then plug everything back in and you are good to go for another 80,000 miles. But what does the spark plug replacement cost? Well, that’s what we are going to cover next.
Spark Plug Replacement Cost
Now we come to the important bit. So, what does the average spark plug replacement cost? Well, the average cost to replace these components is about $120.
But this is only for 4 cylinder engines. The more cylinders you have, the more expensive the spark plug replacement will be. For some cars, a replacement can cost even up to $250 or more. So, beware of this, not all cars are the same and some have more expensive maintenance.
Jiffy Lube Spark Plug Replacement Cost
Now let’s see how much is the average Jiffy Lube spark plug replacement cost. Jiffy Lube has some excellent deals and coupons that could reduce the cost of the spark plug change.
They can change your spark plugs for about $100. Which is less than the average cost of $120. So, if you can get one of their coupons they are an excellent way that you can use to replace your spark plugs.
Spark Plug And Coil Replacement Cost
Now let’s see more about the spark plug and coil replacement cost. How much it will cost you to replace all the spark plugs and coils? The short answer is a lot.
Imagine that the average cost to replace spark plugs is about $120. That is for the spark plugs. The coils on the other hand are a different story. These components can cost a ton of money to get replaced.
A single coil can cost $150. So, whenever you want to replace a coil, make sure that the coil you want to replace is defective. If not, you don’t have to replace it whatsoever.
Conclusion
In this article, we have covered quite a bit when it comes to spark plugs. First, we learned what these components are and why they are so important. Then we covered the causes they tend to fail as well as the symptoms that they produce when they fail.
Then we focused on diagnosing and replacing the components quickly and effectively. Lastly, we covered the spark plug replacement cost and learned how much is it.
F.A.Q
Now let’s answer some common questions.
How Much Does A Spark Plug Replacement Cost
The average cost for replacing 4 spark plugs is about $120 at a shop. The parts alone are about $40 to $60. The more spark plugs your car has the more expensive it will be to replace them. Some replacements can cost up to $250.
BMW Spark Plug Replacement Cost
So, for last let’s discuss the BMW replacement cost. How much it will cost you to replace spark plugs on your BMW? On average for the smaller engines, the replacement cost is about $120. But if you are dealing with a straight-six engine you can expect to pay up to $200 and if you have a V8 you can expect to pay up to $300. The more complex the engine, the more expensive is to perform this service, unfortunately.
Toyota Highlander Spark Plug Replacement Cost
Now let’s see what is the Toyota Highlander spark plug replacement cost. This really depends much on what type of engine the Highlander is running. If it’s a straight-4 engine this means that there are four spark plugs. Which equals about $120 on average. If the Highlander has a V6, then the cost can vary and can get up to $200 since there are more spark plugs that need to be replaced.
