Spark Plugs: What Are They And How Do You Know When You Need To Replace Them?

A car in motion can be seen by automotive enthusiasts as a work of art, particularly if it’s accompanied by the roar of a powerful engine. However, it’s only fair to give credit to the secret architect of this performance; the one that without, it would never move off the start line – the spark plug. Allow Scrap Car Comparison to explain what they do and why it’s so important to make sure they never stop working.

If your car is as good as dead but the problem can’t be fixed with a simple change of spark plugs, you’re probably best off selling it as scrap or salvage. Scrap Car Comparison can get you the very best price for your vehicle, offered by professional scrap and salvage experts positioned all over the UK. Our nationwide network of partner Authorised Treatment Facilities (ATFs) means we can get you a price for your car no matter where you are, and we can even arrange for it to be collected and removed at no extra cost! Give our sales team a call on 03333 44 99 50 or use our scrap car price calculator to get your vehicle valued today!

What Is A Spark Plug?

A spark plug is a small component that is crucial in getting the engine of your car started. It creates a literal spark which is used to ignite the combined fuel and air, which gets the engine moving to power your car. This is the beginning of the combustion process.

Where Are Spark Plugs Located?

Spark plugs are fairly easy to find. Pop your bonnet and take a look at the engine of your car. Immediately around it, you should see a number of cylinders with wires leading from them. These cylinders are where you’ll find your spark plugs. The electricity provided to them is enough to cause a spark which will fire up the engine.

What Causes Faulty Spark Plugs?

The biggest culprit in the case of your spark plugs failing you is simply time itself. Over time, these devices will lose their spark, figuratively and literally. They’ll wear out after years of constant use until they reach a point where they just can’t generate enough of a spark to ignite your fuel.

They can also fail if your electrical systems aren’t working properly. Remember, the spark plugs themselves need something to get them going, hence the wiring that’s attached to them. If they can’t get a high enough voltage, they’re not going to work as they’re designed to.

How To Tell If Your Spark Plugs Need To Be Replaced

There are some obvious signs that your spark plugs might be faulty, with the most glaring of all being a misfiring engine, the inability to get it started or even unsettled behaviour when the car is idling.

That’s not all though; keep track of your fuel consumption, because if your car starts burning through the stuff like it’s going out of fashion, it could indicate a spark plug problem. Slow acceleration and a general reduction of power might also link back to spark plugs on the blink, so if you see any or all of these symptoms, consider swapping them out for some new ones.

How Long Do Spark Plugs Last And How Often Should They Be Replaced?

This can depend on what material they’re made from, with copper spark plugs suffering from wear and tear more quickly than those made from iridium or platinum. The copper variety only has an average lifespan of between 10,000 to 20,000 miles, so if you’ve noticed some dips in the performance of your car around that milestone, dodgy spark plugs could be the answer. If you’ve got iridium or platinum variants you can hope to get double or even triple this mileage. These will often be checked as part of your full or major service.

Can Faulty Spark Plugs Cause A Misfire?

Absolutely. Bad spark plugs can indeed cause an engine to misfire if the spark it creates isn’t strong enough to ignite the fuel/air mixture. They can also be a problem if they’re dirty, as this too can prevent a spark from being generated that would begin the combustion process.

Can You Drive With Faulty Spark Plugs?

If you attempt to drive with faulty spark plugs, assuming you can even get the engine up and running in the first place, you can expect some serious performance issues along the way. Reduced power limiting you to crawling pace, the potential for the engine to give up and stop working to leave you stranded… we certainly wouldn’t recommend it. If you really needed to drive the vehicle to a mechanic to have the spark plugs replaced, it might be possible, but use caution.

Can You Replace Spark Plugs Yourself?

Yes, you can replace your car’s spark plugs yourself if you’d prefer to save some money. First things first, you’ll need to identify the correct type of spark plug for your car. Most retailers will offer this service for free (as an incentive to get you to buy from them) and all they need is your vehicle registration. Alternatively, you can check your vehicle’s handbook which will tell you the specific kind of spark plug you’ll need.

Next, get your hands on the proper tools. A socket spanner and torque wrench will come in handy. You will also need a gap setting tool, since the new spark plugs need to be set at a precise distance to work properly. Copper grease will also help.

Once you’ve acquired the necessary equipment and the engine is cool (never try to do any work on a hot engine) it’s time to remove the ignition leads. These are the wires that lead from each spark plug.

Unscrew the spark plug using the socket spanner and remove it from the well, now measure the gap required by the new plug and set it to that listed in your handbook. Using the copper grease to allow the new spark plug to easily screw into place.

Use the torque wrench to tighten the spark plugs up, then reconnect the ignition leads. Job done.

Can Faulty Spark Plugs Cause An MOT Failure?

Spark plugs may not directly cause your car to fail its MOT test, but there are a number of ways it could lead to this undesirable result. If your engine fails to start, the MOT test simply will not be able to take place. As we’ve already covered above, this could be down to something as minor as a bad spark plug.

Your car could also fall foul of emissions rulings, which can definitely result in an MOT failure. If your spark plugs are dirty, the emissions coming from your exhaust could end up being contaminated which is likely to give you a higher emission reading that you’re allowed.

If dodgy spark plugs are just one of many problems with your current car, sell it with Scrap Car Comparison. With ATF partners all over the UK, we’re sure to be able to get you a price for your car, wherever you are. We can even get it picked up and taken off your hands by professional collection agents at no extra cost! Give us a call on 03333 44 99 50 or use our scrap car price calculator to get your vehicle priced up today!

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