Four Signs You Should Have Your Spark Plugs Replaced

Posted on: 19 June 2018

Your spark plugs are one of the essential parts of your vehicle's ignition system, because as their name indicates, they are the component that literally provides the spark that allows the fuel in the engine to ignite, powering the rest of your car. This means that damaged or malfunctioning spark plugs can negatively affect the performance of your car. Understanding what a few of the signs of bad spark plugs are can help you identify when you should head to an auto repair shop to have them replaced.

Reduced Acceleration

An early sign of spark plugs that are on their last legs is if you notice that your vehicle is having a harder time getting up to speed. Worn out spark plugs cannot provide the proper ignition for your vehicle's fuel when attempting to accelerate, which can lead to slower responsiveness and even reduced top speeds in severe cases.

Reduced Fuel Efficiency

In a very similar vein to the above point, you should also keep watch on how often you fill up your vehicle's gas tank. Damaged and worn out spark plugs will greatly reduce how efficiently your engine is able to operate by altering how well the fuel burns. If this is the case, you will notice a distinct drop in the average mileage that you get from a single tank of gas. eading to a mechanic to have your spark plugs examined straight away is the smart financial decision to make, as waiting too long can cause your increased gas costs to quickly eclipse the cost of replacing your spark plugs.


Another indication that you may have an issue with your spark plugs is if your engine suffers from chronic misfires. A single misfire may be an outlier, but constant misfires point to an improperly operating spark plug. This is a serious concern, as misfires can cause significant structural damage to your engine, which is a much more expensive and complicated repair to have completed.

Ignition Issues

Finally, the most obvious sign that your spark plugs are in need of replacement is if you find that your vehicle is struggling to start, requiring multiple turns of the ignition before starting (or in severe cases, not starting at all). However, keep in mind that ignition issues can be caused by all sorts of issues within your ignition system, which is made out of multiple components, so an inspection by a professional auto service technician is the best way to determine if your spark plugs are to blame.