An ignition coil (also known as a spark coil) plays a crucial role in your engine’s ignition process. As soon as a ignition coil fails, you’ll often notice it straight away from the way the car behaves. The sooner you spot it, the better – because carrying on driving with a faulty ignition coil can lead to more serious engine damage.
What exactly does an ignition coil do?
An ignition coil converts the low voltage from the battery into the high voltage required to create the spark at the spark plug. Without a good spark, there is no combustion – and therefore no smoothly running engine.
Symptoms of a faulty ignition coil
✔️ Stuttering or hesitation when accelerating
The engine runs unevenly and feels as though it’s ‘holding back’ when you accelerate.
✔️ Rough idling or shaking
The engine runs unevenly when stationary – often with noticeable vibrations.
✔️ Engine running on fewer cylinders
If one or more ignition coils fail, the engine will not be running on all cylinders.
✔️ Reduced power and poor throttle response
The car feels sluggish and responds slowly to the accelerator.
✔️ Increased fuel consumption
Incomplete combustion causes the ECU to try to supply more fuel.
✔️ Engine fault light (check engine)
A fault light often comes on, accompanied by error codes such as ‘misfire detected’.
Is it dangerous to carry on driving?
Yes. Continuing to drive with a faulty ignition coil can lead to:
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Damaged spark plugs
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Unburned fuel in the catalytic converter (which can destroy it)
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Poor lubrication and higher engine temperatures
Replacement is often simple and affordable – and prevents a lot of trouble.
Advice from JT Products
At JT Products, you’ll find high-quality ignition coils for virtually all makes. We supply only parts that have been tested for reliability and performance – including for tuned or heavily loaded engines.
Not sure if your ignition coil is faulty? Get in touch with us – we’ll be happy to help with technical advice or a replacement part.
