Smoke from your car’s exhaust is never a good thing. It can be of several colors and can mean that you have to spend some money out of your pocket for repairs, depending on the severity of the situation.
In this article we will only talk about the black smoke, why is it coming out through your exhaust and how to fix it .
What does it mean when your car emits black smoke?
Black smoke means that the air / fuel mixture is no longer done correctly and the car consumes too much fuel. The first thing you should check is the air filter but also the sensors on the intake. The injectors can also be to blame, as can the fuel pressure regulator.
The problem of black smoke can be easily fixed and does not announce a serious problem for the engine, as in the case of a blue-white smoke. But don’t drive like that, first of all the car will pollute excessively and secondly you will consume more fuel unnecessarily.
Pay close attention to the color of the smoke. If it is more gray than black, it means that you have problems with the turbine or the turbo hose may be cracked, in any case it must be investigated.
What are the most common causes of black smoke coming from your exhaust?
1. Faulty injectors
Injectors are directly responsible for the amount of fuel that reaches the cylinders. They spray the fuel, creating basically a fog of fuel. Do not imagine that the fuel actually flows into the cylinder.
When the injector leaks, it is faulty. Practically, every time an injector does not spray the fuel properly, the car will emit black smoke.
If the injectors are malfunctioning they may not close in time and this means that more fuel will get into the mixture, creating a mixture too rich in fuel and eventually the excess will end up in the form of black smoke.
2. Clogged air filter
We are now talking about the second part of the fuel / air mixture. If not enough air reaches the cylinder then the fuel will take the place of the missing air and again we have reached a mixture that is rich in fuel, where too much fuel is burned and black smoke appears again on the exhaust. The air filter can become clogged easily so check it as soon as the car emits black smoke.
We have all seen in traffic at least one car that, when accelerating, suddenly emits a little bit of black smoke through the exhaust. This happens whilst the car is idle or during sudden accelerations, because the mixture is not done correctly and the fuel is not injected in time.
3. Faulty MAF sensor
The MAF sensor decides how much air reaches the engine. If he decides how much air arrives by default it affects and how much fuel will be injected as well . The MAF sensor is extremely important, a faulty sensor will severely affect engine performance.
4. Faulty piston rings
The segments have several important roles in the correct functionality of the engine, one of which is preventing the oil from reaching the combustion chamber. If the segments are defective, the oil will reach the combustion chamber and the car will emit smoke on the exhaust.
5. Defective EGR
The EGR recirculates some of the exhaust gases and passes them back to the engine. If the EGR is defective the car will emit black smoke.
6. Carbon deposits
When the car is started for the first time it has 0 deposits inside the engine. Due to the millions of combustion cycles in the life of an engine, it will gradually accumulate carbon deposits, carbon that will be deposited everywhere inside, all over the injectors, spark plugs, segments, valves, etc. These deposits will affect the engine and it will eventually start to emit black smoke.
Other possible causes for your car to emit black smoke:
- vacuum losses;
- PCM problems with injector control;
- general PCM problems;
- uncalibrated MAF or MAP sensor;
- injector return circuit problem;
- for diesel engines , the car can regenerate at DPF;
- EGR locked on open.
How can you solve the problem of the black smoke emitted by the car?
If you’re lucky, once the car starts emitting black smoke the Check-Engine indicator light will come on. Using an OBD2 scanner you will find out fairly quickly if you have problems with the MAF sensor or the PCM.
If P0101 appears on the scanner, it means that you have a problem with the MAF sensor, P0116 refers to a problem with the cooling circuit, if the thermostat is faulty it will cause a much richer mixture of fuel.
If you are not so lucky, take the above components and check them one by one. Change the air filter, check for leaks, clean the EGR and for injectors you can initially use cleaning solutions that you find in gas stations.
If even after all this you have not fixed the black smoke issue, it means that the problem must be investigated more carefully by a mechanic.