Bad Spark Plug Symptoms

Considered as one of the most abandoned and concealed aspects of a vehicle, a spark plug plays a vital role in keeping the vehicle running. This article will help you with all the information with regards to a bad spark plug.
A spark plug is composed of a shell, insulator, and a central conductor. It is an electrical device that ignites the mixture of air and fuel through an electric spark. Commonly used in automobile engines, a spark plug has the basic motto of starting up the engine.

Spark plugs provide the spark in the engine cylinders thereby aiding in starting the vehicle. It aids in uninterrupted movement of the vehicle, good combustion, improved fuel economy and performance, and low discharge of gases. Lack of sufficient cleaning of the spark plug may lead to its failure within a short span of time. This can create a whole mess of problems, which will manifest in numerous ways. Let's take a look at some of the very regular problems that a spark plug can develop.

Symptoms of a Bad Spark Plug

Rough Engine Idle
Engine idling is wherein the vehicle is stationary with the engine remaining idle, that is without any vehicular movement. An ordinary symptom of a bad spark plug, rough idling exists when the engine stumbles. There is also an escalation in the vibration of the automobile. Not checking the symptom in time could lead to a severe damage, which in turn could prove to be really expensive.

Starting Trouble
This is one of the most common symptoms of a bad spark plug. The vehicle postpones its numero uno function of starting. Even after several attempts, the spark plug fails to produce the spark necessary for vehicle kickoff then there may be a possibility that the battery is running dead due to faulty spark plugs, and hence needs to be replaced at the earliest.

Engine misfire is similar to stammering, wherein the vehicle halts for a fraction of a second and then attains pace. There exists a customary break in the movement of the automobile. The smooth functioning of a vehicle is due to all its cylinders firing. Hence even if a single cylinder interrupts the firing of the engine, it leads to engine misfire. One may note that more contaminated gases are emitted during the misfire.

Engine Surging
In such a situation the vehicle slows down after giving sudden jerks. The engine starts and stops all of a sudden, hindering vehicular movement. Also known as engine hesitation, the engine sucks in more air thereby interrupting the acceleration of the vehicle. Here the engine power works below the usual level. However, occurrence of surging in massive traffic can prove to be dangerous.

Low Mileage
There is a direct relation between the mileage and a bad spark plug. An evident drop in the fuel economy of the vehicle is due to a bad spark plug. The engine performance becomes more deficient when the spark plugs are deteriorated. A malfunctioning spark plug leads to a fall in the mileage of the vehicle. Hence for optimum mileage, it is recommended to check the spark plugs at regular intervals.

Poor Acceleration
This symptom is easily recognizable. The engine performance is hampered and it seems like a postponed signal reaching the engine. In such a situation pushing down the accelerator does not immediately boost the speed of the vehicle. Also it appears like the engine is trying hard to pull the vehicle due to the dull acceleration.

Signs of a Bad Spark Plug

If you aren't very well-versed with the engine of a vehicle, snap the hood and look in for broad wires, positioned in a row along one side of the engine. These are the spark plug wires and the plugs are located at the ends of these wires. Following are some guidelines that will benefit you in understanding as to how bad a spark plug is, and when it needs to be replaced.

Note the vehicle's fuel meter. If the vehicle is literally drinking the fuel, it is an alarm to check the spark plug on priority.
The end of the spark plug should have a light tan or a grayish color, lack of it means that the vehicle is not functioning at normal temperature. Due to faulty spark plugs, the vehicle temperature may rise leading to severe damage.
Look out for carbon deposits or deposits of fuel on the plug. The presence of any one of them, is an indication that the plug needs to be restored without any delay.
The brim of the electrode, when the engine has been used for a while, may look like a sharp point. If so, then it is a feedback that the spark plug has been utilized to its fullest, and requires immediate restoration.

It is very much possible that even though the spark plugs look first-rate, there could be a damage in the spark plug wires. Engine stalling, low power, ignition problems, uneven or rough idling are symptoms of a bad spark plug. Hence be sure to check the wires the next time you open the bonnet. Since the wires are covered with thick insulators it may not be easy to distinguish the error. Hence look in for a rip or a tear in the insulating covering. If there exists an exposure in the insulating material then pay heed to the matter. A very intelligent and effortless way to find out the error is to start the engine at night, and look into the bonnet for any sparks on the wire circumference. It will give you the intimation as to whether the wires need to be restored.

It is however very difficult to grasp the deterioration until the plug wears out. Hence it is considered good, if the spark plugs are changed after every 30,000 miles. This will result in frictionless operation of the automobile. Timely checking and cleaning of the plug is of utmost importance, as it will help identify the problem at the primitive stage itself. This in turn will save the time, money, and energy from being spent. Needless to say, 'A stitch in time, saves nine!'