The 9 Most Common Bad Ignition Coil Symptoms

Your ignition coil is an essential part of your engine, and you need to ensure that it remains in good working order. The timing of your engine is going to be thrown completely off if you’re having issues with your ignition coil. If you don’t get problems like this taken care of, then your car simply isn’t going to be able to keep running. It’s imperative to take bad ignition coil symptoms very seriously.

An ignition coil is going to go bad over time due to certain factors. The most common reason for an ignition coil going bad is due to having a worn down or bad spark plug. This will cause more resistance than usual and can lead to an abnormally high amount of voltage being generated. The resulting heat can actually melt your ignition coil’s wire insulation.

There are actually quite a few bad ignition coil symptoms to consider, so be sure to pay attention to all of them. Once I’ve gone over all of the details, you’ll be able to learn a little bit about what you should do about them.

Bad ignition coil symptoms.

1. Bad Fuel Economy

You need your ignition coil to provide proper spark energy for your engine. When this isn’t possible, your car engine is going to be running far less efficiently. You’ll wind up noticing that your fuel economy is getting worse when you’re going through ignition coil problems. This will lead to more money being spent on gas, and it isn’t something that you’re going to want to allow to continue.

It’s definitely important to make sure that something else isn’t the cause of your fuel economy woes, though. Issues such as dirty engine filters and malfunctioning MAF sensors can also cause problems with fuel economy. Check those out first before assuming that you have a bad ignition coil. These issues are a bit easier to fix.

2. Greater Emissions Than Usual

You might notice that your vehicle has greater emissions than usual when your ignition coil isn’t working right. Hydrocarbon emissions being much higher than normal can actually be a real problem. Some areas have laws against vehicles that have high emissions. If you live in a place that does some type of emission checking procedures, then you’ll want to get this fixed right away.

3. Gasoline Smells Coming From the Exhaust Pipe

If you’ve started noticing a strong gasoline smell coming from your exhaust pipe, then it might be a sign that your ignition coil is not working properly. When your ignition coil isn’t working right, it will make it so that fuel isn’t being burned in the combustion chamber like it should be. This is going to lead to strong gasoline smells, and you’ll want to take note of it. Even if you’re getting faint gasoline smells coming from the exhaust pipe area, it’s going to be something that you’ll want to take note of.

4. Trouble Starting Your Engine

Starting your engine might become tougher if you’re experiencing ignition coil problems. You see, fuel isn’t going to burn properly if the ignition coil isn’t able to do its job. This makes it tougher for your engine to fire up, and you might have to try to turn the car over multiple times before getting it to go. Eventually, your car might not start at all if you don’t get things taken care of.

You should also keep in mind that problems with starting your car aren’t always caused by ignition coil issues. Other common reasons for having trouble starting your engine include starter problems and electrical system issues. You might need to do some troubleshooting to rule things out. Don’t just assume that your ignition coil is to blame without looking into things first.

5. Engine Is Hesitating During Acceleration

Your engine is not going to have the same power that it usually has if the ignition coil isn’t working properly. When you try to accelerate your car, you might even notice substantial hesitation. This can actually be somewhat dangerous, and you don’t want to have to drive a car that isn’t going to be able to accelerate properly when you need it to. This is a telltale sign of ignition coil issues, so you’ll want to take action right away to get things fixed if this is happening.

6. Engine Misfire Issues

The ignition coil needs to work properly so that the engine can keep firing like normal. When it isn’t getting the right energy, misfires are going to occur from time to time. If you’re experiencing frequent or semi-frequent engine misfires, then there is a good chance that the ignition coil is involved. This is going to have a very negative impact on your engine performance, so steps should be taken to address this issue.

7. Exhaust Backfiring

You might even notice problems with your exhaust backfiring. The reason that this occurs is that your fuel particles aren’t being burned in the combustion chamber like they should. This causes them to go down to the exhaust pipe with a higher energy charge than normal. You’ll wind up experiencing these exhaust backfires due to the energy exploding.

8. Check Engine Light

Most people are going to notice their check engine light coming on when they have a damaged or malfunctioning ignition coil. Your sensors are going to detect that something is amiss, and your check engine light will be lit up to alert you to the fact that you need to take action. Of course, check engine lights can come on for a number of different reasons. It isn’t always going to be easy to determine what the cause is if there aren’t other symptoms that can point you in the right direction.

9. Rough Idling

Some vehicles are going to experience problems when idling if the ignition coil is messing up. This isn’t going to happen with all vehicles, though. Some modern vehicles have been made with the right parts to compensate for ignition coil troubles. If your car doesn’t have this feature, then rough idling can be seen as a potential sign that you need to fix your ignition coil.

How to Diagnose a Bad or Damaged Ignition Coil

Now it’s time to take a look at how you can diagnose a bad ignition coil. Even if you’re experiencing one of the many symptoms listed above, it’s still possible that something else could be causing these issues. In order to figure out if your ignition coil needs to be replaced, it’s important to know how to diagnose the problem. It’s also important to understand that different types of vehicles have different ignition coils.

The fact that vehicles have different ignition coils means that you might need different tools just to figure out the necessary information. You might need to have access to an automotive diagnostic scanner with live data capabilities. It’s also possible that you might need an OBD2 code reader, a digital multimeter, and an inductive type ignition analyzer. With so many tools possibly being required, it might be easier to take your vehicle to a mechanic to get the necessary help.

This is an issue that you can fix yourself if you have the know-how and the right tools. It’s just not going to be practical for everyone to accomplish. Try to think about whether you can realistically do this before moving forward. Otherwise, call your mechanic and get things taken care of.

Run Some Tests to Determine the Problem

You’re going to need to run some tests to determine the problem. You can run an engine diagnostic if you can hook your vehicle up to an automotive diagnostic scanner. You might need to use the OBD2 code reader to check things out. This should allow you to get the necessary information to determine if there is an issue with the way the engine is running.

It’s also going to be important to perform a visual inspection. You’re going to want to check out the coil wiring to see if anything is burnt out or corroded. Make sure to check the coil connector for bent pins or loose connections as well. If the coil is damaged in any way, then you’re going to want to repair it or replace it.

Many people will also need to use the digital multimeter mentioned earlier to perform some electrical tests. You’ll want to measure the supply voltage and perform a ground test. You might need to refer to the wiring diagram during this process to get certain pieces of information. This is going to allow you to determine if an electrical problem is the issue.

Replacing a Faulty Ignition Coil

Replacing a faulty ignition coil is not going to be overly difficult if you have the right tools. Before getting started, ensure that you have safety glasses, mechanics gloves, necessary screwdrivers, a wrench, and enough light. You’ll also likely need the OBD2 code reader that was mentioned earlier. You’re going to want to turn the ignition coil switch off and then completely disconnect your vehicle’s battery.

After this, you’re going to be removing the coil connector. How you go about removing a coil connector is going to differ depending on what model of vehicle you’re working on. Generally, you’ll be able to push a plastic tab down and pull out a security harness. There might also be a type of clip that will need to be removed using a screwdriver.

Now you can remove the coil itself. There is going to be a plastic cover protecting the coils, and you’ll need to lift it off to gain access to the coils. The coils are likely going to be attached with two bolts, and you’ll need to use tools to remove them. This shouldn’t take too long, but you should try to be careful while removing them.

Putting the New Ignition Coil In

Now you can put the new ignition coil in. You’re going to want to make sure that everything fits as it should. If you’re encountering any issues, then be sure to check the part number to ensure that you have the right ignition coil. Once this is determined, finish up with installing your new coils.

With the coils installed, you’ll now be able to reconnect both the boil and your battery. Connect the coil first, and remember to put any security clips back on. Now you can connect the battery to finish things up. The last thing that needs to be done is to use your OBD2 code reader to clear your ECU memory.

The purpose of clearing the memory is to eliminate any false data or code that might be present. This is actually a pretty important step, which is why the OBD2 code read is mentioned as a necessary tool. You’ll have to enter the KOEO to accomplish what is necessary.

With that finished, you’ll just need to go through a normal drive cycle. Go ahead and drive the vehicle for ten minutes to see how things perform. Accelerate your vehicle, and get a feeling for whether or not things are performing up to standard. If everything seems good, then you will have just successfully replaced your ignition coil.

In Conclusion

Having to replace an ignition coil can seem pretty intimidating at first. This isn’t the easiest job due to needing to have certain tools that aren’t common. Some people will want to simply take their car to the local auto repair shop to get things fixed. If you have the right stuff, it’s going to be possible to fix things up just fine, though.

Just remember to fix your ignition coil woes as soon as you can. A faulty ignition coil is going to cause your vehicle to perform poorly. You don’t want to encounter any dangerous situations on the road. Take the time to address ignition coil issues, and everything will be fine.




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