How Often Should You Change Spark Plugs? Signs, Cost & How to Guide
Unless you own an electric vehicle, spark plugs will be an important part of your driving life. Luckily, they are designed to last you a long time, meaning you will rarely need to replace them. This does not mean random damages cannot occur, which may require replacement sooner. That said, it’s advisable to change the spark plugs once the car has covered at least 30,000 miles.
Depending on your car usage, you should have the plugs checked every 20,000–40,000 miles. In this article, we will take a look at spark plugs, how often you should replace them, and the negative impact they may have on your car if not replaced at the right times.
What Is a Spark Plug?
A spark plug is a device used to deliver a spark or electric current to the combustion chamber from the ignition system. This allows for the ignition of compressed air, which means a spark plug helps get your engine started.
Benefits of a Spark Plug
Spark plugs are used to aid in the car starting up smoothly and quickly. They also keep the car in tip-top condition, which helps smooth the acceleration. At the same time, they reduce the car’s fuel consumption by up to 30%. According to the EPA, spark plugs help reduce carbon emissions as well.
Signs That You Need to Replace Your Spark Plugs
You may have forgotten about getting your car a tune-up and replacing the old worn-out spark plugs. The following signs may act as a subtle reminder to visit your mechanic for a replacement.
How Often Should You Change a Vehicle’s Spark Plugs?
Most cars have a manual with information about spark plugs. Most manufacturers advise you to change the spark plugs after the car covers at least 30,000 miles. If you bought a used car with no manual, check the spark plugs after you start noticing some of the common problems associated with worn-out spark plugs.
In case you notice something off with your car engine, especially in connection to starting and acceleration issues, first check the spark plugs under the hood of the car.
If the spark plugs seem to have some dirt, it may be that they have an oil leak or carbon deposits. If they are completely worn out or damaged, it may mean that the engine is operating at excess heat levels.
However, always get your spark plugs checked every 20,000–40,000 miles, depending on how much you use the car. For high-performance vehicles, you will need to check the spark plugs more often.
How Much Does It Cost to Change Spark Plugs?
The good news is that changing your spark plugs won’t cost you too much. They typically cost between $16–$100 out of pocket.
If you are new to car repairs and have no idea how to change the spark plugs, hire a professional. With professional labor included, you may part with $40–$150. However, with a bit of experience and the right tools, you can do the job and cut down on costs.
How to Change Spark Plugs
Before you attempt a DIY spark plug change, check the kind of spark plug you need for your car. You will need the following tools:
First, remove the covering on the spark plugs and the air cleaner component. Eliminate any risk of dust getting into the cylinders after removing the spark plugs. You can do this by blowing on the engine to remove any dust and dirt particles.
Pull on the locking tab by removing the ignition coil. Use the connector to disconnect the coil bolt to be able to remove the boot component and the whole coil. Next, use the spark plug wire to remove the boot.
Allow the car’s engine to cool down before you remove the spark plugs. Use your wire puller to position the boot far down at the end of the plug. You can then use the swivel socket to remove the spark plugs.
Before installing the new spark plugs, ensure you space them according to the manufacturer’s recommendations. Use a torque wrench to ensure you have the required amount of torque, as too much will misshape the spark plugs.
Finally, add some lube to the boot of the spark plugs before reinstalling the coil to prevent misfiring and to make any subsequent changes a bit easier. Reinstall the coil’s electrical connector, then bolt and cover in the air cleaner.
Gapping Out a Spark Plug
Gapping a spark plug means leaving a sufficient gap between the center and side electrodes so that arcing occurs at the required voltage to ensure efficient engine performance.
Nowadays, spark plugs come pre-gapped. However, they will need double-checking before installing them in the car.
Should Spark Plugs Be Replaced as a Set?
There is a common concern about whether spark plugs should be replaced as a set, especially when only one is spoilt or damaged. The answer is yes, spark plugs should all be replaced in case one is spoilt. In fact, they come in sets to prevent any problems arising from the difference from switching only one spark plug.
In older cars, spark plugs may be removed and adjusted from time to time and still work efficiently. However, for newer models of vehicles, this is not usually ideal.
How is your car performing? Do you suspect that the car has some spark plug problems? With the information available, you are well set to diagnose spark plug problems and get them replaced. It will not always be a spark plug causing the issues, but ruling spark plugs out in the first place will help arrive at the real problem faster.
Featured Image Credit: Thor_Deichmann, Pixabay