It is not always easy to identify mechanical problems on a vehicle, the engines are more and more complex, more and more loaded with electronics and making a diagnosis often requires a few years of mechanical experience. Fortunately, some problems are fairly well known and easily identifiable, such as smoke problems.

In this article we will try to help you understand why does your car smoke black and graze? It is very often a combustion problem that is the cause of these types of symptoms. To help you, we will first explain to you what are the causes of this kind of problem, then, secondly, what to do to prevent your vehicle from emitting black smoke and browsing.

Why does my car smoke black and graze?

So we start our little guide by explaining the origin of your concern. As we told you in the introduction, this kind of problem very often comes from a combustion problem. Even though black smoke and a engine that grazes are not necessarily related symptoms, it is very common to notice them simultaneously. We will explain to you in turn the origin of each of these problems.

car that grazes and smokes black

Causes of a car emitting black smoke

We start with the most common part of your worries. Your car's engine smokes black, and you don't understand why. You are right to worry about it, identifying thick smoke is not normal, it is not necessarily serious but it is better to worry about it before a major repair is necessary to resolve this problem which may be trivial.

  • A bad air / fuel mixture: Black smoke is a sign of pollution and unburned fuel scraps, which implies a overconsumption of your vehicle. Indeed, if you do not burn all of your mixture, you will necessarily consume more to achieve the same performance. The problem can therefore lie either in a mixture that is too rich in fuel, or in a mixture that is too lean in air. Because, for novices, combustion is carried out with a mixture of fuel (gasoline or diesel) and oxidizer (air), it is an unbalanced ratio between the two which can cause this thick black smoke.
  • A dirty engine: A tired or clogged engine can cause a bad air / fuel mixture, it is generally a problem of pressure in the cylinders which generates a lower operating temperature and which does not allow all the fuel to be burned and therefore little by little. little to foul your engine.
  • An air intake problem: As you have understood the problem can come either from the air or from the fuel, it is possible your air inlet hoses are cut or have a hole, which would directly impact the volume of air supplied to the engine. A clogged air filter can also cause this kind of problem, the same for the turbo if your engine is equipped with it.
  • injection: These are the injectors which manage the quantity of fuel sent into the cylinders, if they are clogged or badly wedged they can be responsible for a car which smokes black or which grazes.
  • The lambda probe or the flowmeter: These two instruments are sensors which must, in conjunction with the computer, manage the intake of fuel into the engine, a failure on one of these two components will completely disrupt the combustion of your fuel mixture and disrupt the behavior of your vehicle. .
  • Too smooth driving: It's sad, but responsible and safe driving can sometimes lead to engine fouling. If you do not drive regularly enough at high engine speeds, you risk fouling your engine.

The causes of a car that grazes

As we have seen above, the two concerns are not necessarily linked, but know that they are both very often present. In fgeneral, a car will first emit black smoke and over time start to graze. It is generally when the behavior of the engine is directly impacted that we start to really worry about this kind of symptoms, except, the more we take care of it quickly, the less the bill turns out to be high.

If your car is grazing, you must feel power losses during acceleration, or some sort of hiccups or jerks which clearly shows a lack of power. In addition to the issues we touched on just above, it is also possible that this is related to an ignition problem (remember to check the condition of the candles) or a dirty tank, to do this, check the condition of the fuel filter. If your diesel car emits a lot of jerks while driving, do not hesitate to consult our dedicated article on this subject for more information and solutions to your problem.

thick black smoke and spurts on my car

What can I do to prevent my car from smoking black and grazing?

Now that you know why your car smokes black and grazes, and that you've diagnosed your problem, it's time to fix your car and get it to work properly again. You will understand that some concerns cannot be solved without advanced knowledge of mechanics, but you can without worries try to clean your engine by two simple techniques:

  • Use a specific additive to clean your engine: This is the most used solution, especially before technical inspections for old cars that no longer pass the pollution control, it is also most certainly something that will happen to you if your car emits thick black smoke. These are usually bottles that can be found in any automotive center for 15 to 20 €. You add it to your fuel and follow the directions, it can do your engine a lot of good.
  • Perform regular scrubbing yourself: Nothing could be simpler, we talked about it in the first part, but many people drive in "under-revving" without necessarily realizing it. It is important to preserve your engine, but unfortunately not enough stress to clog it and can cause jerks and thick smoke. We therefore advise you regularly to Warm up your engine and run for 15 to 20 minutes in high revs to burn off any unburned fuel soot.