Ignition Coil change & replacement made easy

An ignition coil is a transformer that increases the 12v supply voltage to in excess of 50,000v to provide the spark plug with maximum power to produce an electrical arc from its electrode to the plugs earth.

• Mechanic will read the ECU for possible fault codes related to the ignition system.
• Mechanic will inspect the ignition system and spark plugs.
• If necessary, the mechanic will replace the ignition coil pack(s)
• Mechanic will advise if any other parts need to be replaced.
• Mechanic will check if the ignition system works correctly again and will test drive the car.

Unless you are a qualified mechanic with the required skills, training and equipment to do the job, we strongly recommend an ignition coil or coil pack replacement is only carried out by a professional mechanic. ClickMechanic can help get you a vetted and local mechanic to carry out the work. Just enter your postcode and your car's registration number at the top of this page and select the work needed to get an instant fixed price up front.

The main symptoms that can occur when there is a faulty ignition coil are;

• When starting the car is problematic.
• When the engine cuts out after starting.
• When the engine does not run smoothly (the engine misfires).
• When the car vibrates excessively.
• When the 'Check Engine' light on the car's dashboard is on.

An ignition coil or coil pack replacement usually takes around 1 hour, but can take less or more time. Ultimately, the time that the job will take will depend on a number of factors, like your vehicle's make and model, year, as well as other factors. Select your car at the top of this page for information on job time and cost for your vehicle through ClickMechanic.

Ignition coils are critical to the smooth running of an engine. Without them, the engine will simply not work as it should, if at all. Therefore as soon as you are advised that the ignition coil(s) need changing, you should do so. Running an engine with a faulty ignition coil can also cause additional wear and tear on other items.

Ideally, even if there are individual ignition coils per cylinder, they are replaced as a set and not individually. On engines where there is one coil pack covering all the cylinders, there is no option in this.

If you suspect there is any issue with an ignition coil or there are concerns about its condition, book with a professional mechanic as soon as possible to get it checked and replaced if necessary, driving the vehicle may lead to further complications or damage.

Although an ignition coil check itself is not part of the MOT test, a faulty ignition coil may cause your vehicle to misfire when you accelerate and this can lead to an MOT failure (for example due to it causing an emissions issue).

The symptoms of a failing ignition coil can include:

• Engine misfires
• Vehicle may vibrate or experience juddering
• Reduced fuel economy
• Decrease in engine power

No, you should not replace your ignition coils with spark plugs. While both components are necessary for your vehicle to run, they serve different purposes and are not interchangeable.

If you have one bad ignition coil, it’s possible that the others may go bad soon. Replacing all of them will save you the hassle of having to replace them one at a time.

There is no specific time period for when you need to replaced ignition coils, however, it's good practice to get them checked during an annual service and inspected for wear and tear every 50,000 miles or so.