Renault 21 Plugs

You can buy your plugs with confidence at GSF Car Parts. We keep a huge range of reliable plugs in stock allowing you to maintain and self-service your car. We have both spark plugs and glow plugs available to purchase, and with our easy search tool, you can find your correct plugs by entering your reg number or by selecting your vehicle's make and model.

We offer a large range of branded car plugs at our stores and warehouse. Stocking the most reliable brands of spark and glow plugs including Bosch, NGK, and Denso. 

Plugs are essential in the ignition process of starting your car or van. If your car is having trouble starting, it might be time to replace your spark plugs or glow plugs.

What does a Spark Plug do?

Spark plugs are only fitted in petrol engines. They fit into the spark plug socket of your vehicle where they kickstart your ignition. They do this by transmitting electrical energy that ignites the mixture of fuel and air in the combustion chamber. This makes the engine start. 

There is one spark plug per cylinder. For example, a four-cylinder engine has four spark plugs with four spark plug sockets. 

How long do Spark Plugs Last?

Spark plugs are designed for long-term use and are pretty durable so only need to replace them between every 80,000 and 100,000 miles.

What are the Signs you need to Change your Spark Plugs?

You may need to change your spark plugs if your car has problems starting or is misfiring.

What does a Glow Plug do?

Glow plugs are similar to spark plugs but they only are used in diesel cars and vans due to the different ways they work. A glow plug operates by heating incoming fuel and air to deliver efficient fuel combustion in a diesel engine. The glow plugs light will indicate that they are warming up before you can start the engine. Fuel combustion will then start your engine using the glow plug.  Like a spark plug, each cylinder has one glow plug.

What happens when Glow Plugs Fail?

Factors you might notice if your glow plugs fail:

• Experiencing starting problems
• A misfiring engine
• Low performance of the engine
• Poor acceleration

If you notice any of these symptoms with your diesel vehicle, you should start by changing your glow plugs to see if this gets your car back up and running. We also do many other ignition system parts for a complete overhaul of your ignition system. This includes ignition cable kits, distributor caps, contact breaker points, and rotor arms.

Shop Plugs at GSF Car Parts Online and In-Store

All our plugs are from trusted brands in the motoring industry, so you can count on them to be reliable and of excellent quality. Plus, our low-price promise means you can always expect great value too.

We offer free UK delivery on all online orders over £25, plus 60-day returns*. So, buy plugs from us with confidence today. Or if you’re close to one of our 190 store locations across the UK & Ireland, just drop by and our experienced staff will be able to direct you to the right part for your vehicle.