Engine
What is an Ignition System?
Creates the spark that fires the engine (petrol only).
Simplified animation — not to scale.
In plain English
The full chain that creates and delivers the spark on a petrol engine: battery, ignition coils, spark plug leads (older cars) and spark plugs.
A simple analogy
"It is the engine's match — every cylinder needs a perfectly timed strike, thousands of times a minute, for the car to run smoothly."
How it works
The battery supplies power, the ECU times each spark, the coil boosts the voltage massively, and the spark plug fires it across a tiny gap inside the cylinder to ignite the mixture.
Signs of trouble
- ⚠Hard starting, especially when cold or wet
- ⚠Misfires and rough idle
- ⚠Loss of power
- ⚠Worse fuel economy
Rough UK cost
£80–£600 depending on which parts are replaced (diesels don't have one)
Parts: Varies by part
Labour: Varies by part
Always get a written quote. Prices vary by car, region, and parts brand.
Heads up: Carautonomy is for general guidance only. If your car is showing warning lights or behaving oddly, get it looked at by a qualified mechanic.