Replacing a bad spark plug is as easy as pie. Anyone can change spark plugs with little to no hassle. But sometimes, you may need to hire an expert or go to a service center.
With the right toolset, spark plug replacement can be done without any help from experts. It will surely save you time and money. And it will also make you confident to fix other problems with your car.
In this “guide”, you will get a practical guide on how to change a spark plug at home with some essential tools. For those who want to go in-depth, I’ve also discussed when and why you should change the spark plug.
When to Replace Spark Plugs?
A spark plug should last around 30,000 miles (ranging from 20,000 to 40,000 miles). But the actual lifespan may vary from brand to brand. So you should check your manufacturer’s manual. Usually, you can change the spark plug after its recommended period of usages.
If the spark plug gets faulty before its expected lifecycle, you must fix it or replace it with a new one for better performance. But I recommend replacing the plugs instead of fixing them.
How to Change Spark Plugs?
This is probably the easiest guide on spark plug installation available on the internet. Whether you are a novice or a mid-level expert, you can change the spark plug at home by following this simple step-by-step guide.
What tools do you need to replace spark plugs? First, you have to collect the following things to start the process.
Things Needed to Replace Spark Plugs
- Spark Plug Tester
- Vacuum and/or compressed air blower
- Socket/ratchet set
- spark plug wrench
- Torque wrench.
- New Spark Plugs
- Anti-seize compound
- Microfiber towels
- Safety gloves
- Safety glass
Step-1: Detaching all the Spark Plugs
- First, disengage the negative terminal of the battery.
- Remove the cover if available.
- Using a vacuum or compressed air blower, clean the surface around the igniter to get rid of dirt and grime.
- Detach the spark plug boots one at a time with the spark plug remover. The engine starts in a specific order, and it has the utmost importance to keep that order. Therefore, use a labeling method, for example, tape to mark which wires lead to which plugs.
- Take off the ignition plugs orderly, and keep them separately for inspecting the damage.
Step-2: Identify Faulty/ Defective Spark Plugs
(i) After a certain period of use, all spark plugs will get dark to some extent. Usually, they become brownish or blackish just by regular usage.
Anyway, you have to look for carbon, oil, or gasoline buildup on the ignition plug. If any of these are available, then these could be significant problems that need further diagnosis.
(ii) Now, check if the center electrode is okay. But if the spark plug is on the way to exceeding its recommended period, then you should change it anyway. Because the health and performance of your car substantially depend on the spark plug.
And spark plugs are not that expensive as well. So replacing (before the recommended period) with a new one would be a great and wise decision for sure.
(iii) You can keep using your existing spark plug if it’s in mint condition. However, you surely need to check the gap by using a gap measuring tool.
If the sparker gap matches the manual-specified gap, then it’s okay. Otherwise, you have to adjust the gap. Place a soft microfiber towel on the surface if you need to use a hammer for adjusting the plug gap.
Then you should throw the bad sparking plugs away and replace them with new components.
Step-3: Installing New Spark Plugs
The latest sparking plugs may come with presets from the manufacturer in most cases. Despite that, you should check whether it is pre-gapped or not. With a gap gauge, you can simply check the gap of the new sparkers.
Now it’s time to hand-thread the new plugs back into the engine with the socket extension. If you feel it’s hard to do this, pull it back out and repeat the same process. Lastly, you have to cross-thread the plug.
By using a torque wrench, you must tighten the sparking plugs according to the torque specification of your automotive device.
Then re-engage the plug boots to their particular mates. Finally, re-engage the battery. Once you have done the process, you must start the car to ensure that the sparker is correctly installed.
What are the Most Common Symptoms of Faulty Spark Plugs?
Engine misfiring: When the faulty sparking plugs delay the combustion effect, the engine will misfire instead of running smoothly and steadily.
Hard starting: If you face difficulty starting your car, then it might have defective sparkers.
Engine knocking: Owing to the faulty sparkers, you may hear that your engine makes a distinct knocking sound while accelerating.
Rough idling: The faulty spark plugs may cause rough idling. When the sparkers perform perfectly, your engine sounds smooth and stable. But if your engine has one or more bad ignition plugs, this may sound rough while idling. The car also may vibrate.
Fuel economy degradation: Facing a sudden drop in fuel economy is one of the main symptoms of having faulty sparkers. If you face the same situation, your engine may contain a defective one or more.
Safety Measures While Changing Spark Plugs
- You have to wear safety glasses and safety gloves.
- Must check the instructional manual from the manufacturers.
- Complete one spark plug (removing, inspecting, and installing) at a time to void mixing one with another.
- Of course, you have to make sure that the engine is cool before starting the changing process.
- You should disconnect the battery before changing sparkers.
- Avoid over-torquing and over-tightening the spark plugs.
Whether it is easy or hard to change the spark plugs, you can certainly do it yourself in most cases. If your car is fitted with a complex engine, then you should get help from an expert. In general, it’s an easy and straight task for most beginners.
By following our tutorials step by step, you can change the defective sparkers yourself. Do not forget to collect the tools you need to perform this action.
If you need more assistance on getting the torque and gap spec, please let me know what year, make, model, and engine size it is, and I can definitely help you with that.
Greetings from James Milan. I am an Automotive enthusiast and car repairing expert for over 12 years. Blogging is one of my hobbies. According to my interest, I’ve started this blog to share my thoughts about the Automotive sectors and hope you’ll love it.