11 signs of bad spark plug wires |Symptoms of a Bad Spark Plug Wires

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Are you looking for the common signs of bad spark plug wires? we will cover all that in this post. Spark plug is one of the things in a car you shouldn’t take for granted likewise the spark plug wires.  So today we are going to look at some symptoms and signs of bad spark plug wires that way you can tell when to change them.  

These 11 symptoms of bad spark plug wires are ideally the common and most obvious signs you will see when your plug wire is bad.   

I will give you my one cent on the question is “ does changing spark plug wires improve performance”?

signs of bad spark plug wires | Symptoms of a Bad Spark Plug Wires

For a car engine to function optimally, the spark plug must be in perfect condition. The size of a car plug is small, but the function is incredible. When the spark starts getting bad, the general performance of the engine will be limited.

Ideally, a car plug wire transfers electrical power from a vehicle ignition system to its engine spark plugs. If the spark plug is in good condition, the engine works fine. That is to say, without the spark plugs, the engine won’t work. When a car starts acting sluggishly, the spark plug can be the problem.

Spark plugs are not what you buy on an annual basis. Spark plugs stay longer before it goes bad. A normal spark plug has a greyish white insulator, while that of a bad spark plug is covered with substances/stains like oil and fuel.

Expectedly, a clean and good spark plug ensures a normal engine operation. When it starts going bad, there are signs/symptoms to look out for. With these symptoms, you should replace the spark plugs.

Before we get to the symptoms let look at a question we got recently which is “does changing spark plug wires improve performance?”  

 Related Article:  Spark plug Replacement cost

Does changing spark plug wires improve performance?

Well, my response to this question is yes, and that is because the spark plug wires are what makes possible for the spark plug to get the required voltage jolt of electricity from ignition coil in other to ignite the spark plug. So without a good spark plug wires ignition of the plugs will not occur.

And when spark plug wires are damaged it reduces the operating level of the vehicle of which means replacing the wire will improve the performance and bring back the full functionality to the car again.

Watch this video to see how you can replace a bad spark plug wires.

11 signs of bad spark plug wires | symptoms of a bad spark plug wires in cars.

Here are the 11 signs of bad spark plug wires to take notice of then you are ready to change your plug wires. Mind you, in some case it not just be a bad wire. it could even be a bad spark plug itself and this why this article will guide further on missing spark plug and what to do or not do.

  • #1-  Reduced gas mileage

There’re other symptoms of a bad spark plug wire to look out for, but reduced gas mileage is common signs of bad spark plug wires and can be very frustrating too. Mileage is a number of miles covered. A good spark plug and wires in good conditions can cover much distance(s), but with a bad spark plug wire, your journey can be shortened.

  • #2 – Hard starts

When your car refuses to start, it might not a battery fault but, a bad spark plug wire. Hard starts is one of the most common bad spark wire issues. Bad plugs can also drain the battery, stopping the engine from picking up. If you are certain it is not a battery issue, then you should replace the spark plug as soon as possible.

  • #3 – Engine misfiring

Engine misfiring is one of the known symptoms of a bad spark plug wire in a car. This usually occurs when there is incomplete engine combustion. Engine misfires, because the cylinders are not working or firing fine. With a bad spark plug, the vehicle will halt and continue. When the spark plug wire is bad, it will cause an erratic flow of electrical current to the engine.

  • #4 – Slow acceleration

Next signs of bad spark plug wires are slow acceleration. A poor acceleration is a quick way to tell you that the spark plug wire is faulty. All you need to is to change the spark plug.

Don’t forget to also read this article:  Can you drive a car with a missing spark plug?

  • #5 – Rough engine idling

Rough engine idling is also an electrical issue that develops when the spark plug wire is bad. It is also a common symptom that needs an urgent replacement of your spark plug. A bad spark plug wires can affect the smooth flow of electrical current which can cause a rough engine idling.

  • # 6 – Poor fuel economy:

Poor fuel economy in a car is a worrisome situation. There could be other reasons like a catalyst issue. But, a bad spark plug wire is a suspect. When the spark plug is bad, the fuel economy decreases due to incomplete combustion. Get a new spark plug and the fuel economy will be back to normal.

  • #7 – Reduced engine power

A reduced engine power fault is a result of a cut or break in the spark plug wire. When this happens, the engine will not function optimum, or it may not even start at all.  For proper engine combustion and maximum engine power, the spark plug wire must be in good condition to ensure electrical current is passed into the engine.

  • #8 – Engine surging:

When you notice an engine surging issue in your car, act fast. This is a common sign of a  bad spark plug wire in a car. An engine surge happens when there is a short spurt of sufficient electrical flow. Engine surging occurs when there are cracks or broken wires outside the insulation. Without an adequate flow of electrical power, the engine won’t pick. Engine surging is one of the symptoms of a bad spark plug. Replacing it will get your car back on the road.

  • #9 – Knock-like noises from the car:

Usually, no knock-like noises should be considered as ‘’nothing’’. This kind of noise can be a sign of a bad spark plug wire. This can be noticed from the force of the pistons, which means the combustion is not working. To prevent other issues from coming up, get a new spark plug.

  • #10 – Vehicle Engine light comes on:

You’ll probably need the service of an auto mechanic or an auto electrician that will use computer to help you check or scan to see if the engine light is on. A bad spark plug can cause engine misfiring which can also set on the engine light. An illuminated engine light is one of the symptoms of a bad spark plug wire.

  • #11 – Car Engine hesitation

 And the last symptoms of bad spark plug wires on the list here is engine hesitation.  Engine hesitation can possibly mean your spark plug is bad. It usually happens during acceleration. Engine hesitation occurs when there is inadequate electrical current flow to the engine. The amount of electrical current from the car battery to engine is not adequate. This can cause an engine to hesitate. Getting a new spark plug will remedy the situation.

Conclusion on Signs of bad spark plug wires

The car plug is linked to engine performance. Spark plugs is a very important component in the engine. Spark plugs ignites the combustion chambers to burn the mixture of fuel and air to enable the vehicle to move.

When the spark plug is bad, the engine will not function well. Usually, car spark plugs last long. However, the longevity depends on the type of spark plug. Spark plugs are made from durable materials that can withstand tons of explosions before it starts getting bad.

When you see any of the listed symptoms, that means it is high time you got a new spark plug. There are different spark plugs in the market. When replacing a spark plug, it is important you get the same brand and model of spark plug that the vehicle came with. YOu might want to check some recommendation on Amazon with links below.

These are the signs of bad spark plug wires we will cover in this post. I hope this article helps helped you place feel free to share.

Read Next: symptoms and reason for a Misfiring Spark Plug

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