Common Ignition Coil Failures: Symptoms And Solutions!
All cars have an ignition system with one or more ignition coils. Ignition coils are designed to convert low battery voltage into the high voltage needed to fire the spark plugs. If you want to know what problems it could present, we bring you here the symptoms and common failures of the ignition coil .
Because ignition coils are such an integral part of the ignition system, they almost always cause noticeable symptoms when they fail. It is good that you read this post until the end so that you do not get a surprise.
What does the ignition coil do?
An ignition coil is a transformer that converts battery voltage into the tens of thousands of volts required to ignite the spark plugs . The operation of the ignition coil is based on a phenomenon called electromagnetic induction, a process that uses a magnetic field to generate electrical current.
Inside the coil are two sets of coils. The so-called primary windings contain hundreds of coils of wire, while the secondary windings have thousands of coils of wire.
When the ignition coil is energized, battery voltage flows through the primary windings, creating a magnetic field. Open-circuiting the coil causes that field to collapse, causing tens of thousands of volts to be induced in the coil’s secondary windings. The high voltage from the secondary windings then travels from the coil to the rest of the ignition system .
It is important to note that there are different types of ignition coils. Older vehicles have a single ignition coil that is connected to a distributor via an ignition wire. The high voltage travels from the coil to the distributor , which, in turn, distributes that voltage to the individual spark plugs and wires.
Newer vehicles use Coils with Spark Plugs (COPs) or coil packs. Engines with a COP ignition system have one ignition coil per cylinder. Each coil sits directly on a spark plug.
For its part, a coil pack is a group of ignition coils combined into a single molded block . With this design, each cylinder has its own ignition tower but shares its coil with a mating cylinder.
Symptoms and common failures of an ignition coil
You should test an ignition coil to determine if it is bad. There are several test methods available. Do you think your car may have a bad ignition coil? If you are experiencing one or more of the following symptoms, you may be correct.
1- Engine failures
Since ignition coils play a role in igniting the engine’s fuel-air mixture, a bad coil can easily cause a misfire . This occurs when there is incomplete (or no) combustion within one or more of the engine’s cylinders.
The phenomenon will be felt as a hesitation or tremor when the car is running. You may notice that the problem intensifies when the engine is under heavy load (accelerating, for example).
2- Illuminated check engine light
In modern cars, a computer (often called a powertrain control module) looks for problems that could cause increased emissions from the vehicle.
One of these problems is a common engine ignition coil failure caused by a faulty coil. The PCM usually detects the misfiring (and possibly a problem with the coil electrical circuit) and turns on the check engine light.
3- The car does not start
While newer engines have one ignition coil per cylinder, older vehicles use a single coil to supply voltage to all the spark plugs. If that one coil fails, none of the cylinders will get spark, resulting in a no-start car .
4- The engine stops
Like most electrical devices, common intermittent ignition coil failures can be experienced. When this happens, the engine may stall unexpectedly. Shutdown occurs mostly on engines with a single ignition coil.
5- Reduction of fuel consumption
A faulty ignition coil often causes the engine to misfire and run poorly , leading to reduced fuel economy.
Can you drive with a bad ignition coil?
A bad ignition coil can damage other parts of the vehicle, such as the catalytic converter, powertrain control module, and even the engine. A defective coil must be replaced immediately to avoid major problems in the future.
