7 Signs Bad Or Worn Spark Plugs
Spark plugs are an important part of the ignition system of gas vehicles. Replacement is part of your car’s recommended maintenance plan, but knowing the most common symptoms of a bad spark plug is still helpful.
This guide covers the bad symptoms of spark plugs. It also explains the functionality of a spark plug, shows where it is, and provides tips for testing it. Finally, I will finish the article with the costs of replacing the spark plug and some answers to the questions.
Bad Spark Plug Symptoms
If the motor light flashes, the spark plug may get worse. Faulty plugs can also lead to misfire engines, rough idle, accelerated problems, hard-start engines, reduced fuel consumption, and exhaust gases that smell like fuel.
This is the most important symptom.
1. Check Blinker Loyalty Engine Light
If the spark plug is bad, the air fuel mixture cannot burn if necessary. Therefore, if the associated code is defined in the system, the check engine will be displayed. If the spark plug is contaminated with oil or too hot, the light can compete.
If the motor is blinking and checked by the engine, it can indicate that the spark plug has failed and one or more cylinders do not remain functional. You need to stop driving immediately and fix the issue.
Remember that check engines can occur for a variety of issues. Because of these warning lights, it cannot be assumed that the spark plug is simply bad. Instead, you should check the diagnostic problem code in the scanner and look at the online code library to see what’s going on.
2. Failed engine
The ignition system is so stressful that it causes misfires. This can occur at any time if the sensor fails or if the spark plug is defective. Misfire conditions create sputtering and feel like there is a problem with the engine. Allowing the engine to continue to be missing will lead to further damage.
3. Louter Idol
Normal car leaves travel occurs between 600 and 1,000 rpm. If everything is needed, you will see a consistent idle from the car. However, if the plug fails, the idling will be rough. If the idling becomes rough, you may feel vibration.
4. Route acceleration
If the spark plug fails, you will notice some issues with acceleration. Pushing the accelerator pedal may make the car seem slower. It can also feel rough when the engine tries to express more power. However, this is another of these issues due to some of the ignition systems. It could be due to a defective sensor, a poor ignition coil, or something in the fuel system. For this reason, a full diagnosis is required before assuming that the spark plug is responsible.
5. Heart Start Engine
Considering turning the car key and going beyond the engine, you can first think of the starter system. This system is extremely important, but you also need a great spark plug to make the engine a reality.
If the spark plug does not ignite the air mixture in the cylinder, the engine will not run. Even if there is only one plug bad, it may be possible to operate the engine, but it doesn’t run smoothly.
6. Poor fuel consumption
For your car to reach EPA’s estimated fuel consumption, the engine must run at an optimal level. Every time the spark plug is defective, you can expect the engine to work better than it needs to. This additional work will require more fuel. The result is a reduced fuel consumption until you run the melody and replace the spark plug.
7. Gas exhaust odor
If the spark plug does not ignite the entire aircraft mixture, the system will lead to unbroken gas. It pushes out the exhaust and causes a strange gas smell.
This smell indicates that there is too much fuel or too little air. This problem can be caused by insufficient fuel injectors, defective mass airflow sensors, or blocked air filters.
Spark plug function
Spark plugs have a main purpose. They are designed in a way that ignites the air fuel mix. When electrical energy is transmitted by the spark plug, it eventually jumps over the gap and ignites this mixture of cylinders.
The plug temperature is adjusted as the instructions precede when the temperature reaches high. On the other hand, if the plug is too low, contamination will occur. The spark plug has a heating area that shows how well the heat is distributed.
Where is the spark plug?
Spark plugs are electrical devices that are adapted to cylinder heads of internal combustion engines. The spark plug is connected to the ignition coil, creating the tension required to create the spark.
The number of spark plugs most engines have is directly related to the cylinders of the car. Usually there is one spark plug per cylinder. Therefore, the four cylinder engines have four spark plugs, and the V8 has eight plugs. The biggest exception to this rule is the Hemi Engine. These cylinders make two spark plugs each home. The 8-cylinder Hemi has a total of 16 spark plugs.
Can I test the spark plug?
There are several ways to check for spark plugs and determine if they work. We recommend starting with a visual inspection. It’s similar to an entry when the spark plug works properly. If it looks normal with a slight red coating, it simply means that inferior fuel is being used. This should not indicate an engine problem.
Here are a few visual indications of problems:
1) Fuel-fouled: shiny coating on the tip and side electrode due to a rich fuel mixture, ignition problems or a low spark plug heat rating
2) Detonation damage: shows the engine timing is off
3) Worn plug: needs to be replaced
4) Carbon fouled: blackened tip and side electrode due to a rich fuel mixture
5) Pre-ignition: burned side electrode from running too hot
6) White spark plug tip: Lean air-fuel mixture
7) Oil ash fouled: caused by worn piston rings and seals
8) Mechanical damage: from extending too far into the combustion chamber
There are more advanced ways of checking a spark plug, although most home mechanics aren’t going to travel this route.
Grounding Test Steps
1) Pull out the fuse for the car’s fuel pump to cut the supply.
2) Run the motor until the fuel is burned out of the system.
3) Remove the spark plug from the cylinder head.
4) Connect the spark plug to the coil pack.
5) Put the spark plug on a surface that’s grounded.
6) Crank the ignition while you watch for a spark.
- If the spark is blue and strong, it’s fine.
- If it is dull orange and weak, it’s not strong enough.
- If there’s no spark at all, the plug needs to be replaced.
Multimeter Test Steps
1) Run through steps one to three of the previous section.
2) Set your multimeter to ohms.
3) Test the resistance between the probes to ensure an accurate reading.
4) Test the plugs by touching a lead to the terminal end of the plug and another to the electrode.
Check the reading against the manufacturer’s specs in your service manual. Most of the time, a 4,000 to 8,000 ohms reading is normal.
How Much Does It Cost To Replace The Spark Plugs?
On average, you can expect to spend between $100 and $500 for a spark plug replacement. Spark plugs typically cost $5 to $20 each, depending on what type of car you drive and the quality of plugs you choose. Considering your car may need between four and 16 plugs total, you could spend $20 to $320 just on the parts alone.
If you replace the spark plugs yourself, you won’t owe anything for labor. In some cars, this isn’t a tough job to complete, but there are some cars that have plugs that are difficult to reach.
If you prefer to have a professional perform the spark plug replacement, you may spend $50 to $250 on labor, depending on how many hours it takes. Additionally, the labor rate makes a difference.
If you aren’t comfortable changing your own spark plugs, we recommend taking it to a professional. As mechanics that have performed countless spark plug replacements, we can’t stress enough how costly it becomes if a spark plug breaks off in the cylinder because the job isn’t performed right.
How often should spark plugs be changed?
Many auto manufacturers recommend changing the spark plugs after the first 30,000 miles. However, the optimal replacement schedule depends heavily on what type of spark plugs you use. Some types have a life of up to 100,000 miles or more, often worth paying extra for.
Can I drive with bad spark plugs?
The vehicle may still drive with bad spark plugs, but you shouldn’t continue operating it. With a fouled plug, the engine isn’t running right and the air-fuel mixture doesn’t burn correctly. You could break down anywhere and you are allowing more damage to occur, especially to the catalytic converter.
What do bad spark plugs sound like?
The spark plugs won’t make any strange noise, but the rough-running engine can create noise. It can lead to a strange vibration that is felt throughout the entire cabin. Additionally, if the engine misfires, you are going to hear a loud sound from the motor.
What does a misfire feel like?
A misfire feels like the engine has lost power temporarily. You may notice the hesitation most often when you try to accelerate. It can also create a louder noise as the engine attempts to run normally. Additionally, a misfiring engine reduces fuel economy, causing you to go through more gas.
Are spark plugs easy to change?
The job isn’t as simple as replacing a car battery, but you may be able to do it at home. If the spark plugs are easy to access and you have the right tools, you can change them yourself. However, if the plugs are hard to reach or you are having trouble getting them out, it might be best to visit a mechanic.
Changing the spark plugs is a task that should be done regularly to keep the engine running at its best. You should follow the maintenance schedule offered by the manufacturer to determine how often the plugs should be changed.
You can also change the plugs if you notice any performance issues. If other parts aren’t running as they should, the plugs could fail prematurely. Additionally, running the car with bad plugs can cause other, more costly problems, such as a bad catalytic converter. For that reason, you shouldn’t put off a spark plug replacement when it’s needed.