Symptoms Of A Bad Ignition Coil

In this article, we will be talking about Symptoms Of A Bad Ignition Coil. Symptoms Of A Bad Ignition Coil vary from vehicle to vehicle and may include: rough idle, lack of power or acceleration, and engine misfire. Symptoms can also include exhaust smoke, loss of oil pressure, and the smell of raw gasoline in the air intake.

Bad Ignition Coil

What Is An Ignition Coil?

The ignition coil is an essential component of the car’s engine. It helps to start it by transforming 12 volts from your battery into thousands of volts that are needed for combustion, which means you won’t be able to drive off without starting. The coil consists of a core wrapped with copper wire that has an electronic circuit inside.

The voltage from your battery is sent to the ignition coil through the ignition switch, and when you turn the key to start your car, that voltage is increased and sent to the spark plugs. When an ignition coil fails, it produces a low voltage or, in some cases, no spark at all.

Ignition wires can be a source of trouble for car owners. They’re responsible for ensuring that your vehicle has proper electrical signals to start and will give you an error message if anything goes wrong with them, so it’s important not only to check when the engine light comes on when there is actually something wrong!

The first sign could simply mean bad connections or worn brushes, which would affect performance, but more often than not, these symptoms point towards more serious issues such as voltage regulator modules going up against their limit causing overheating while alternatively, fires might develop due to accidents within this area since everything gets pretty close together without any room left over for any mistakes. Following are the Symptoms Of A Bad Ignition Coil:

  1. Difficulty Starting The Engine
  2. Engine Misfire
  3. Poor Fuel Economy
  4. Check Engine Light
  5. Diminished Power
  6. Sudden Backfires
  7. Sooty Exhaust

Let’s explain them one by one.

Difficulty Starting The Engine

If you have trouble starting your car’s engine, there could be multiple problems. One possibility is a faulty ignition coil that causes the problem and makes it difficult for an otherwise-healthy vehicle to start up every time before leaving on any long trip or just needing to drive in general.

Fortunately though, as mentioned above, these issues aren’t always connected, which means if everything else seems ok with no slipping clutches, then this may not necessarily mean anything about bad coils at all.

Engine Misfire

One of the most common symptoms is an engine misfire. When the ignition coil malfunctions, it doesn’t send the proper signals to your engine, which means it won’t fire correctly. Symptoms of an engine misfire include shaking or vibrating in the car, rough idling, and a lack of power.

There’s a problem with your engine if it misfires or stalls when you’re sitting still, stop at red lights and then accelerate. This could be an indication that one of the cylinders isn’t firing correctly. So this means there is something wrong with how they’re getting fuel into each cylinder connectivity between them because sometimes these types of problems are just wonky wires inside our cars!

The ignition coil is the nerve center of your car’s engine. It creates sparks to each individual spark plug which powers it into action, and when this gets wrong, there are many symptoms that can occur, including increased emissions or even worse-stalling.

Poor Fuel Economy

A car’s fuel efficiency can be affected by a number of factors, but when you notice that it is getting fewer miles per tank than before, this could indicate your ignition coil needs to be replaced. It happens because spark plugs aren’t receiving enough power, and so the system will compensate with more injection leading to poor performance in terms of engine response time as well as higher emissions levels.

Check Engine Light

Your check engine light will be on when there’s something wrong with your car, like an ignition coil. If you drive without addressing the problem and ignore this warning sign from mechanics, then it could cost thousands in repairs.

Diminished Power

If you notice that your car is acting sluggish when it’s idling or during acceleration, there could be a problem with its ignition coils. This will make the engine run roughly and result in reduced power as well, which can cause stalls on some vehicles.

Sudden Backfires

A backfire is a loud noise that occurs when unburned fuel suddenly escapes from an engine’s exhaust system. While there are a few causes, such as failing ignition coils and other problems with your car’s muffler or tailpipe, it most commonly happens because of excessive residue buildup inside, which can lead to significant damage if left unchecked for too long!

Suppose you notice any strange smells coming out of vents near where you would expect them. In that case, cleanliness might not necessarily enter into consideration when considering just how much more serious this issue may be becoming over time.

Sooty Exhaust

If you see black soot coming out of the exhaust pipe, this could be another sign that your ignition coil needs replaced. It’s also a sure sign that there is an issue happening with your car’s fuel system, and if not addressed quickly enough, this could lead to more serious problems down the road.

How To Test An Ignition Coil?

If you’re unsure whether or not your ignition coil is broken or just dirty, there are a few easy tests that can be done on it. One is to test the coil’s resistance with a multimeter, and another is to measure how much voltage it’s putting out. If you’re not the DIY type, then taking your vehicle to a local mechanic should be able to test this connection for you.

What Do Ignition Coils Do?

The ignition coil is an electromagnet that creates high voltage electricity to help your engine ignite its fuel by creating a spark between the plug and the cylinder head. It works like this: the coil’s core gets energized by the car battery, which then sends an electrical charge to one end of the primary winding.

This creates a magnetic field around the core, and when it’s turned off, the energy stored in that magnetic field will discharge through the secondary winding, which is connected to the spark plugs.

Why Does Ignition Coil Fail?

There are a few reasons why an ignition coil might fail, but some of the most common ones are:

  • Age: Over time, the ignition coil will wear down, so it’s best to replace them at regular intervals
  • Heat: This can cause the coil to expand, which reduces its ability to create a spark between the plug and cylinder head
  • Dirt: Over time, dirt can accumulate inside the ignition coil, which affects its performance levels
  • Water: If the ignition coil gets wet, it can short out and stop working completely

Replacing an ignition coil is a relatively easy process, and you’re looking at spending between $150 to $400 depending on the type of car that you have.

You can tell if your ignition coil is failing by checking for any of the symptoms mentioned in this article, and if you’re not comfortable doing the repairs yourself, then take your vehicle to a trusted mechanic who can do it for you.


A bad ignition coil may affect the car’s performance. The article has provided some great details about what to look for when you suspect your vehicle might have an issue with its ignition system. If you think this could affect your engine’s function and want more information on how you can get it fixed, then contact us today! That’s all we have on Symptoms Of A Bad Ignition Coil.

Frequently Asked Questions

How can you tell if an ignition coil is bad?

The easiest way is to listen. If a person hears a clicking sound when they turn the ignition, then an ignition coil may be bad. Poor tube or cylinder compression can also indicate that one or more of the engine’s eight coils for spark plugs has failed, which would again cause a ticking sound. In this case, there may also be misfires, so it is important to have the car inspected by a mechanic before driving it any further.

What happens when you have a bad ignition coil?

The ignition coil is the device inside your car’s engine that generates electricity to turn over the engine and make it run. When an ignition coil goes bad, it usually means one of these two things: (1) The electrical current coming out of the spark plug has too much resistance or gets “leaky” for some reason, or (2) There are no sparks at all.
If this happens, your car won’t run. Electronic ignitions involve both digital signal processing and pulse-width modulation circuitry in some way, so when either logic gate fails, you’ll find yourself unable to start up that ignition system.

Can you drive with a bad ignition coil?

Yes, but it is like driving with a bad spark plug. The car will run poorly and eventually get worse and worse until you get the problem fixed.

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