Symptoms of burnt spark plugs in the car: what are they and what to do?


What are spark plugs in cars?

Car spark plugs are those electrical devices that produce the spark that starts the combustion of the fuel inside the engine. Car spark plugs are, in fact, the "fuse" that allows the controlled ignition of the fuel inside the cylinders that generates the energy needed to move the pistons and then move the car. It is no coincidence that the specific term for spark plugs in cars is"car spark plugs".


The way spark plugs work is very simple. The car's injectors fill the engine cylinders with a precise mixture of diesel or gasoline and air. To start the engine, the spark plugs come into play, using the electrical energy contained in the battery to generate a spark. This spark ignites the mixture in the carburettor which pushes up and down the car's pistons which, through the transmission, make the wheels turn and move the car.

When the car' s spark plugs are fouled or burnt, symptoms immediately appear which, if detected quickly, result in a few euros for repair.

What is the car's spark plug light?

The car spark plug light or car glow plug light is represented by a yellow line that twists twice to create a shape similar to a yellow spring. The glow plug light always stays on for a few seconds as soon as you turn the key and ignition, nothing abnormal.

However, if the spark plug light stays on for more than a few seconds or if it starts to flicker, then there is a problem with the spark plugs in the car. The light may indicate dirty spark plugs, burnt spark plugs or spark plugs that are struggling to warm up due to severe cold, especially if the car is parked outside in winter.


Unless the symptoms of burnt spark plugs are clearly evident, it is best to wait a few minutes with the dashboard on. If the outside temperature is low, we can also try to move the car to a warmer, sheltered place or, in the worst case, call a mechanic to come and inspect it.

What are the benefits of good spark plugs?

The biggest benefit of car spark plugs in good condition is knowing that the car will always start smoothly. Having good quality car spark plugs in good condition is a great way to ensure other benefits for your car as well. Let's see what the benefits of well-maintained car spark plugs are:

  • Fuel savings - several studies have shown that faulty, burnt or overly fouled car spark plugs can increase fuel consumption by up to 30%. In addition to saving the environment, the cost savings of a more efficient engine is a good excuse to have the spark plugs replaced as soon as there are symptoms of burnt spark plugs.
  • Stablefuel combustion: When the spark plugs in cars work correctly 10 times out of 10, perfect fuel combustion is achieved and the whole car benefits. Many of the car's problems are due to imperfect fuel combustion that does not allow the engine to run under the best conditions.
  • Start theengine quickly and decisively - there is no time wasted trying to start the car several times or having to resort to a forced start. Good quality spark plugs prevent problems starting the car and save us time, money and stress!
  • Reduced emissions - one of the benefits of good spark plugs that is often overlooked is the reduction of harmful gases released into the environment. This is due to better combustion of the fuel, which by reducing the final residue produces a cleaner exhaust gas.
  • Reducedmaintenance costs: good quality automotive spark plugs from well-known brands may cost a few extra euros per part, but they provide greater reliability and longevity. If the spark plugs burn out less easily, you end up going to the mechanic less often and reduce your car's maintenance costs. Poor quality spark plugs are a guarantee of a return to the garage after a short time.

What are the symptoms of burnt spark plugs?

Burnt car spark plugs can be a pain in the ass for any motorist. If even a single spark plug burns out, it can lead to deterioration in driving quality and engine performance. Let's take a look at what the symptoms of burnt car spark plugs are:


  1. The engine strug gles to start - one of the first symptoms of burnt car spark plugs is difficulty starting the car. If a burnt spark plug is fitted in the first cylinder of the ignition cycle, it may even be impossible to start the car.
  2. Engine misfire warning light on - the second symptom of a blown spark plug that emerges is the illumination of the engine misfire warning light. This warning light can indicate a wide range of abnormalities, including a combustion problem with burnt spark plugs.
  3. Slowor hard acceleration: One or more burnt car spark plugs can cause the oxygen sensors to incorrectly analyze the engine's gas output and the ratio of oxygen to fuel. When incorrect data is sent to ECU, it regulates oxygen/fuel level.
  4. Increasedfuel consumption - another symptom of burnt spark plugs is increased fuel consumption due to difficulty in creating a spark at the optimum time. This anomaly makes it necessary to use more fuel for the same amount of energy and therefore fuel consumption increases.
  5. Engine blows and vibrates - when the spark plugs are working perfectly the engine does not make any particular noise. One of the symptoms of burnt spark plugs is the popping noise that comes from the incorrect combustion of the fuel inside the engine cylinders. This anomaly generates an easily audible crackling and sometimes even vibrations throughout the car.
  6. White smoke from the tailpipe - if some of the fuel remains unburned during the normal combustion cycle, white smoke may appear from the tailpipe. This white smoke is a clear symptom of burnt spark plugs.

What problems are caused by burnt spark plugs?

If the symptoms of burnt car spark plugs are neglected in the long run, several problems can occur. In the worst case, it becomes impossible to start the car, creating quite a few organizational problems if you are disconcerted away from home or a mechanic.


In general, any anomaly in the ignition of the car should set off an alarm on the burnt spark plugs. In most cases the battery and alternator are responsible for car ignition problems because of their complexity and because they are more delicate than the spark plugs. The non-stance is useful to keep in mind that even burnt spark plugs can result in a broken down car.

What to do with burnt car spark plugs?

If you are sure that you have burnt spark plugs or notice various symptoms of burnt spark plugs, the best thing to do is to confide in a mechanic right away. After a careful check he will be able to tell you if the spark plugs need to be replaced or if they need a simple cleaning.

Many motorists think that the only thing to do is to take them apart and wipe them with a cloth, but although the procedure seems easy, it needs to be donecarefully. It's best to trust the people who do it for a job and avoid creating more problems than before.

Fortunately, when the symptoms of burnt spark plugs appear, the car can still be driven safely and efficiently. This allows you to schedule a visit to the mechanic without too much haste after evaluating the different options. With Pistonudos you go directly to a network of selected and specialized mechanics with whom you can have peace of mind.



Add a comment from Symptoms of burnt spark plugs in the car: what are they and what to do?
Comment sent successfully! We will review it in the next few hours.