Spark Plugs – How Tight Is Right?

The humble spark plug is an often overlooked but very important part of your vehicle. Their job, believe it or not, is to provide a spark that will ignite the fuel and air mixture within your engine. Just like any other part of your engine, spark plugs need to be properly installed and having them too loose or too tight can be detrimental to the health of your vehicle. The size and ideal tightness of a spark plug is determined by the make and model of your vehicle.

You would be surprised to find out how many times we have had a car brought in only to discover the issue is poorly installed spark plugs. Lot’s of us have had to change a spark plug in a mower or other devices with basic engines which can lead to a false sense of confidence in regards to installing them in your car. Let’s take a look at what you can expect from your engine if your spark plugs are not installed correctly.

If Spark Plugs Are Too Loose

Given that spark plugs are crucial to maintain the proper rhythm required to run an engine smoothly, most of the signs that your spark plugs are too loose will come in the form of poor or unreliable engine performance. If your spark plug is too loose these issues will only get worse over time as vibrations within the engine bay will cause the plug to get looser over time as you drive. As these symptoms can lead to bigger problems down the line you want to get it sorted as soon as possible.

Sings a spark plug might be loose starts when you try to get the car running. While starting troubles can be caused by a wide range of parts, a loose spark plug will result in the car struggling to get going. When it does you will likely find that acceleration is slower and rougher than before. This is due to the third sign we are looking at which is engine misfires that are caused due to misfiring. This means it’s time to bring your car or truck into a professional before permanent damage occurs.

spark plug installation

If your loose spark plug starts to overheat it can cause something called pre-ignition to occur within your engine block. This happens when the surface of the plug becomes so hot it ignites the fuel-air mixture on contact instead of when it sparks. Pre-ignition leads to random combustions within the engine which results in pinging or knocking. This can be heard while driving and means you need to bring your car in right away as improper detonation can lead to engine damage or total failure.

If Spark Plugs Are Too Tight

The repercussions of your spark plugs being too tight are not nearly as bad as having them too loose. Having said that, it can lead to a damaged engine which is always an extremely costly outcome. It is very common for spark plugs to be installed too tight because it makes sense for something in your engine to be as secure as possible. Only with experience can you work out the right tightness to get the best results and reduce the chances of something going wrong.

A spark plug that has been installed too tight can sometimes seem impossible to remove. This is because grime, debris and corrosion can act as a sort of sealant which, in the worst case scenarios, can make removing the plug all but impossible. The good news is a professional with the right tools and proper understanding can get it out. Things get a little worse though if the bolt hole becomes stripped during the process, resulting in a replacement not being able to be fitted.

installing spark plugs

If the spark plug’s tightness causes parts of the insulator or the plug itself to break apart it can result in small pieces making their way into the combustion chamber. Any foreign object that makes its way into your combustion chamber has the potential to cause harm to your engine. This only reinforces the idea that while a spark plug is a cheap component that is easily replaced, it can lead to significant issues if left unchecked or handled poorly.

Having An Auto Electrician Install Spark Plugs

If you are confident in your own mechanical abilities you can certainly perform a check to see if your spark plugs are installed at the correct tightness. Making sure the engine is cooled before checking is a must as they will be extremely hot after operation. You can check if they are loose by seeing if you can turn them by hand. If you are unable to make the plug turn with a tool such as a wrench, they may well be too tight. The best course of action is to bring it into an experienced professional who understands the right way to install spark plugs.

At Bashi’s Auto Electrical we have qualified auto electricians with decades of experience, working with just about every make and model of car and truck you can think of. We provide obligation free quotes before carrying out any work. We stock a massive range of new and used parts which means we can find the right plug for your engine should they need replacing. To talk with a professional auto electrician about any concerns you have about your spark plugs, give Bashi’s a call on 07 5495 7333 or contact us online.