Spark Plug change & replacement made easy

The engine's spark plugs provide the spark in the combustion chamber to detonate the fuel and air mixture in order to force the piston back down and thereby rotate the crankshaft.

• 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 full set of spark plugs
• 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 a spark plugs change 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 spark plug 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.

On average a spark plugs change will usually take 1 hour, but can take anywhere from under 1 hour to 1.5 hours. The time that the job takes will depend on a range of factors. For example, 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.

Spark plugs 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 spark plugs need changing, you should do so. Running an engine with a faulty spark plug can also cause additional wear and tear on other items.

Spark plugs are always replaced as a set and not done individually.

The only thing you can do in reality is to use good fuel as this will improve the combustion and prevent the build up of deposits.

Manufacturers service schedules for spark plug changes should be adhered to all tie to prevent issues from arising with older plugs.

If you suspect there is any issue with a spark plug or if there are concerns about its age or 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. Bad spark plugs can cause engine misfires and lead to potential engine damage and overheating of the catalytic converter.

Spark plugs are used to create a spark that ignites the air-fuel mixture in the engine's cylinders, which in turn powers the engine.

The type of spark plugs you need for your car depends on the make, model, and year of your vehicle. This information can usually be found in the owner's manual or by using online part finders such as Bosch Aftermarket and NGK part finder. You can also input your reg number and postcode on our website and we'll get you a price for the correct spark plugs replacement for your vehicle.

If you don't replace spark plugs periodically, they will eventually wear out and will no longer be able to create the spark necessary to ignite the air / fuel mixture in the engine. This will cause the engine to misfire, lead to poor fuel economy and in some cases the car may not start at all.

When spark plugs are faulty they can cause damage to the catalytic converter as well, and lead to an increase in harmful emissions.

While you are technically able to drive a few thousand miles with faulty spark plugs they can cause multitude of problems such as poor fuel economy, reduced performance and even damage to the engine. It is highly recommended to get them replaced as soon as possible.

It's generally advisable to replace all of the spark plugs at the same time since they will most likely have the same amount of wear. This also helps ensure that all of the spark plugs are firing as they should together, which can help improve engine performance considerably.

Replacing spark plugs does improve performance. New spark plugs can improve the performance of your car’s engine by up to 30% as suggested by the National Institute for Automotive Service Excellence. This is because fresh spark plugs help improve the combustion cycle of the engine, which makes your car’s engine more efficient.

Yes, you can change spark plugs without changing the wires, but it's not recommended. Over time, spark plug wires wear out and become less effective at conducting electricity. This can cause engine misfires.

Faulty spark plugs may cause an MOT failure if the engine is not running smoothly, or if the spark plugs are excessively worn. If you suspect the spark plugs may be faulty, it is best to get them all replaced before the MOT test.

On average a spark plug change costs around £85. Depending on the damage caused to the wires, they will also need to replaced which bring the average total cost to about £100. As this cost will change depending on the make and model of the car, you can get an exact price for your car by entering your postcode and vehicle registration number at the top of the page.

If you don't replace spark plugs, the vehicle will eventually have starting and performance problems. The engine will run less efficiently, and it may be difficult to start the vehicle. In a worst-case scenario you can even expect the car to not start at all.

Whether it's worth buying expensive spark plugs will often depend on the type of metal used to manufacture the spark plugs.

Currently iridium spark plugs are the most expensive on the market as they're made of rare earth metal. Iridium plugs typically last longer, have a higher melting point, and create a more powerful spark. This means they help your car’s engine run better, and they last longer.

In fact, many iridium plugs come with a 20,000-mile guarantee, which means you can often go years without changing your plugs.