Ignition coils are a type of induction coils that are used in internal combustion engines to provide the spark that ignites the air-fuel mixture.
They are typically composed of two cylindrical coils of wire wrapped around a common iron core. The primary coil is wound with a relatively low number of turns of heavy wire, while the secondary coil is wound with many more turns of much thinner wire.
When a current is passed through the primary coil, it generates a magnetic field. This field induces a current in the secondary coil, which is then passed through a spark plug to create the spark that ignites the fuel-air mixture in the engine’s cylinders.
Often times, ignition coils fail. When that happens, does that mean you should replace all the ignition coils at once? No. One coil pack is designed for two engine cylinders, and a replacement should only be done when that specific pack is damaged. One defective coil pack won’t affect other ignition coils, and hence no need to replace them all at once.
How Does a Coil Pack Work?
A coil pack is a type of ignition system that is commonly used in many modern vehicles. It is an alternative to the more traditional distributor-based ignition system.
In a coil pack system, there is one coil for each spark plug. The coils are mounted on the engine and are connected to the spark plugs via a set of wires.
Coil packs were first introduced in the 1980s and have become increasingly popular in recent years. Many newer vehicles come with coil packs as standard equipment.
There are several advantages to using a coil pack ignition system. One advantage is that it can help improve engine performance.
Another advantage is that it can reduce emissions. Coil packs are also less likely to fail than other types of ignition systems.
How Long Do Ignition Coils Last
Generally, ignition coils will last over 120,000 miles or 5 years, whichever comes first. However, there are a few factors that can affect the lifespan of your ignition coil.
If you drive in stop-and-go traffic or short trips, your ignition coil may not last as long because it doesn’t have a chance to cool down fully between uses.
Additionally, if you frequently use aftermarket spark plugs that are not the correct heat range for your vehicle, this can also cause premature failure of your ignition coils.
Finally, if you live in an area with high humidity, this can also shorten the lifespan of your ignition coil.
What Makes Coil Pack to Malfunction
Ignition coils malfunction when one of the following occurs:
- The coil’s primary or secondary winding fails.
- The coil’s insulation breaks down, causing a short circuit between the windings.
- Internal damage to the coil pack – If there is any internal damage to the coil pack, it may not be able to generate the high-voltage spark needed for combustion. This can be caused by physical damage, water damage, or simply age and wear. For example, the coil’s internal resistor burns out.
- The coil becomes loose on its mounting, causing a poor connection between the coil and spark plug.
- The coil’s wire terminals become corroded or damaged, causing a poor connection between the coil and spark plug.
- Incorrect installation – If the coil pack is not installed correctly, it may not work properly. This could be due to incorrect wiring, incorrect spacers, or other factors.
- Foreign material such as oil, dirt or moisture gets into the coil, causing it to malfunction.
Ignition Coil Replacement Cost
The average replacement cost for an ignition is between $65 and $350. This depends on the model and the make of your car.
Labor costs are approximately between $50 and $150, and again this range depends on the auto garage and your city of residence.
This range does not include taxes and fees, and does not factor in your specific vehicle or unique location.
How to Replace a Bad Coil Pack
One of the most common issues that can occur with any vehicle is a bad coil pack. Before you begin, ensure you have the correct tools and replacement parts. You’ll need a socket set, a ratchet, and an extension cord. You’ll also need a new coil pack, which you can purchase from most auto parts stores.
- Disconnect the battery. This will prevent any sparks from occurring while you’re working on the engine.
- Locate the coil pack. It will be located near the engine, and will have a number of wires running to it.
- Disconnect the wires from the coil pack. There should be four or five of them.
- Remove the bolts that hold the coil pack in place.
- Install the new coil pack in the reverse order of removal. Make sure all the wires are connected properly, and then reconnect the battery.
Signs and Symptoms of Failing Coil Pack
Check Engine Light
Another symptom of a failing coil pack is a check engine light that comes on. This can be caused by a number of things, but the check engine light is accompanied by other symptoms of a failing coil pack, the coil pack is likely the root of the problem.
One of the first signs of a failing coil pack is engine misfires. If one or more of the coils in the coil pack are not functioning properly, it can cause the engine to misfire.
The engine may run rough, feel like it is shaking, and produce less power than usual. Pinging or knocking sounds may also be heard coming from the engine.
Engine Performance Issues
If a coil pack fails, it can cause several engine performance issues. The engine may have less power than normal, it may hesitate or stall, and it may produce strange sounds.
Increased Fuel Consumption
Increased fuel consumption is a common symptom of engine problems. If you notice an uptick in your car’s fuel usage, it could be a sign that something is wrong with the engine.
It could be a sign of a failing coil pack. This is because the misfiring engine is not running as efficiently as it should be, and therefore is using more fuel than normal.
Related: How many ignition coils does a car have?
Hi I’m Marshall based in 1478 Doctors Drive Santa Monica, CA. I’m your DIY Car Repairman with more than 5 years experience in automobile repair, a skill I learned from my old man.
I started this blog to share my experience on both simple and technical aspects of your car.