Can Bad Spark Plug Wires Cause Rough Idle In 2022?
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Spark plug wires are one of the most significant parts of your vehicle. It is related to the car’s electrical and ignition system. These wires are also responsible for bad performance.
Sometimes your car is rough idling, and bad plug wires might be the reason behind this. But most of the time, people ignore this kind of problem. That is why solving these common problems become a headache sometimes. Therefore, can bad spark plug wires cause rough idle?
The answer is positive. To learn more details about it, follow the article till the end. Let us also show you the reasons.

What is Rough Idle?
Idle means maintaining low RPM without an accelerator after starting the engine. It is vital to provide enough power to the engine to run smoothly. Rough idle means your vehicle is facing some difficulties maintaining a steady rate of rotation.
The most probable reason is improper mixing of fuel and air, which causes enough lacking to ignition power. Several reasons are behind of engine’s rough idle. Spark plug wires are one of them.
Spark Plug Wires
Mainly, these wires are electrical connections to the combustion chamber, which ignite the fuel mixtures. When an electrical signal comes to the plug, it produces a spark.
To burn fuel, we all know that we have to ignite it, and then it starts the burning process. As an ignition source, all you need is a spark to the ignition coil. Therefore, spark wires are the most crucial factors here.
How do They Affect the Idle?
The idle speed has to be consistent means no skipping. The standard speed range should be between 600 to 1000 RPM. When you start the engine, the rotational speed starts to gather enough power to generate the vehicle. But if there are any bad spark wires, this process interrupts to generate power.
When a plug wire is old or damaged, it cannot ignite properly—another way to say that no spark will produce to the ignition coil. Again, if there is no spark, fuel will not burn, and the engine cannot gather the energy to start or idle. Sometimes damage wires get stopped to spark in midway.
The engine will not idle properly and might be backfired. You can also hear some wired sounds or vibrations and feel some shakings. Malfunctions occur in ignition coils due to bad spark, and it causes rough idle.
Why Will They Interrupt Idle?
The answer is pretty simple. As we discussed, idle is wholly related to the engine’s ignition. Again, the ignition system is entirely dependent on spark plug wires. That is because electric signal produces spark through these wires.
Therefore, the ignition coil receives the spark source through them. As for the engine, the ignition system is the most crucial part. Then you can say any malfunction of ignition-related components will cause rough idle.
Bad Spark Plug Wires Symptoms
You can easily notice when the spark plug wires are not working. The first noticeable event is the misfiring of the engine. When you try to start the engine, it misfires with some wired noise. If the bad wires continue to work, your vehicle will lose the power to accelerate.
Even you will face some difficulties while you try to start the engine. Another thing to notice is fuel economy. Improper ignition power will reduce the fuel economy of your vehicle. Sometimes you would notice physical damage when you open the engine. It will also hesitate in acceleration time.
When Will You Change the Wires?
You will easily notice the facts about bad spark plug wires. When the engine has got RPM, there must be some wire problems.
Again, if you look at the fuel economy, check out the leakage or damaged wires. The engine also misfires and hesitate to accelerate due to damaged wires. It would be best if you replaced them immediately. Many experts suggest replacing plug wires after completing 30,000 miles or every four months.
Should You Stop Rough Idle?
There are many reasons why you should stop the engine’s rough idling. You might not realize it, but it can harm you in several ways. Let us discuss them in brief,
Environmental Issues
We all know that burning fuel produces carbon di-oxides, carbon mono-oxides, and other residues. During rough idle residues, production becomes higher than usual. If you idle the engine for about 10 to 15 minutes, pounds of residues will emit into the environment.
Bad for Engine Health
A rough engine is also bad for your car. Rough idle is sure to cause misfires, hesitations, low accelerations. These types of actions reduce the engine’s longevity. It would also damage the exhaust system.
Prohibited
Some professionals have prohibited engine idling for more than a minute. If you do more than that, rough idle can occur. It also hampers the engine’s lifetime.
Health Issue
The residues from idling also have effects on your health. That is because most of them are detrimental to health. You might accidentally inhale them, and it can cause you some diseases.
Do not Idle Longer than Usual
Most manufacturers suggest idling for 10 to 20 seconds while you start your car after a long interval.
How to Avoid Rough Idle?
To ensure a better engine life, you should avoid rough idle. If you are looking for a service center, do not go to a cheaper one instead of a reputable one. Always maintain a regular service to check the engine’s condition.
The most important thing is to replace the wires when it is necessary. When you start the engine, let it warm for some time. To avoid rough idle, remember to follow these things or else it will cost you a fortune.
Bottom Line
Now we can say that you learn, “can bad spark plug wires cause rough idle or not?” look after your vehicle by good service and use. Wish you good luck.