It is possible to replace only one ignition coil if you notice that it is faulty. When you do it, you should also replace the spark plugs with the coils so you won’t have to remove them twice. Mechanics might suggest changing all the coils when one becomes faulty, but the decision is yours.
If you listen to their advice, you should ask them about the reasons behind changing each of them. Make your assumption and make the best decision based on the facts.
Your car will experience several malfunctions, such as engine misfiring, which happens when you accelerate. In some severe cases, your car can shut down completely while driving. When this happens, you become a danger to other drivers and should pull over to the side of the road.
Because one of the cylinders fired incorrectly, the misfire led to a complete engine shutdown. Replacing your ignition coils is crucial now, and you cannot drive your car before you fix this problem. Seek the help of towing services that will transport your car to the nearest auto repair shop.
If your budget is tight, replacing the broken part will solve your problem. But because the repair shops will also charge for labor, most people choose to replace all of them.
Should I replace ignition coils with spark plugs?
If these parts fail, the spark plugs cannot function properly. They are two separate parts that rely on each other. Most people also decide to replace the spark plugs when installing new ignition coils on their vehicles. If spark plugs are too worn out, they can create unnecessary loads on the coils.
It is strongly recommended to replace both components at the same time if the spark plugs are the cause of ignition coils failing. However, replacing them is unnecessary if you are replacing the spark plugs during routine maintenance. Remember, ignition coils should always be replaced only when they are failing.
If the system also features plug wires, replace them if they are worn or damaged. While replacing these broken components is a fix to your problem, you should also consider its cause and eliminate the source before more issues appear.
Contact a mechanic and ask them about replacing these parts with spark plugs. Let them inspect your car and diagnose any possible problems. They will determine whether you should replace both of these parts or only the spark plugs.
Are all ignition coils the same?
These parts are not always the same as they come in various shapes and sizes. You will find out that the distributor-type ignition system relies on one or more ignition coils to jump the spark plug gap and efficiently ignite the fuel mixture.
New ignition coils will feature designs that are more specific to their applications. However, some universal options are still available. You can find the canister-type coil in breaker-point ignition systems. It is a popular design among manufacturers because they are easier to make.
But their shape and size are always identical. The only way manufacturers differentiate each other is through the labeling applied on the side. Before purchasing a replacement, you should ensure this part is compatible with your car.
ENA
Here’s an example of one that works with various car models.
| Name | ENA Ignition Coil Pack |
| Compatible with | Toyota & Lexus |
| Installation Type | Bolt-On |
| Item Dimensions LxWxH | 9 x 3 x 6 inches |
| Item Weight | 9.6 ounces |
Pros
- They have hundreds of positive reviews.
- It works for a Lexus & Camry.
- Installation is easy.
Cons
- It doesn’t work for every car.
Signs to look out for
It is not difficult to test whether the coil packs need to be replaced. You have to ensure they are properly working and you can do this whenever you perform a routine maintenance inspection. Use an Ohm meter to test the,m but don’t forget to approximate the tool values according to the ignition coils.
Check the owner’s manual to find the values of your ignition coils. The manufacturer should specify this information. If you cannot find the manual, search your car model online and seek help from other owners that drive your type of vehicle.
Additionally, you can tell if it is bad just by noticing the symptoms. Some of the most common signs of a bad coil pack are:
- Noticeable lack of power
- Louder engine
- Blinking check engine light
- A significant drop in RPMs when accelerating
- Rough idle
- Smoke from the exhaust
Will they throw a code if something’s wrong?
Several signs will warn you about this part’s poor condition when a coil pack goes bad. For instance, the check engine light will come on as it detects the problem. The car computer knows when something goes wrong. In some newer models, it will also display a trouble code.
Additionally, you will notice that your car has increased emissions. If you do a state emissions inspection with a bad coil pack, your vehicle will not pass the test. Furthermore, you will be able to notice a reduced fuel economy due to incomplete combustion.
If you have to refuel more often, take your car to a repair shop and have it inspected. That is why you should always prioritize this problem and fix it as soon as possible.
| Error code | Department | Most common reason |
| P0350 | Ignition coil | Malfunction in a circuit |
| P0362 | Ignition coil | Communication issues in the electrical circuitry |
| P0300 | Engine misfire | Damaged spark plugs |
| P0312 | Engine misfire | Damaged spark plugs |
What causes them to keep going bad?
Ignition coils are durable parts designed to last a long time. However, they are not indestructible and will not last forever. Often, they fail because of bad spark plugs or plug wires. If your car’s fuel mixture is too lean or too rich, they will fail earlier than expected.
The heat and vibrations generated by the engine will speed up this process and shorten its lifetime. Wear and tear can happen to any engine block part, including the ignition coils. Their insulation will degrade and cause them to overheat.
If conditions are ideal, they should last for the entire lifespan of your vehicle. If they break down eventually, you have to replace them immediately as your car will not function properly without them.
