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The color of the exhaust gases – what it means?

The color of the smoke coming out of the exhaust pipe can tell a lot about the car's condition.
Exhaust gases an efficient working cars are virtually colorless. If the smoke is colored there may be a problem with the drive unit.


White billows do not always have to mean that the vehicle's something wrong. If after some time from starting they stoped to appear, you probably do not have to worry about. White smoke is often simply gathered steam for example in the exhaust system. It is better to see if the prevailing low temperatures.

White and in addition dense exhaust gases which escape from the system despite travelled the greater distance  is, however, a bad sign. Perhaps it has been damaged gasket under head or head itself. White smoke arises from the fact that the cylinder enters the liquid coolant. We can feel the irregular work of engine or a loss of power and notice the loss of liquid coolant.


The blue color of exhaust gases is a sign that the engine burns oil penerate to the chambers. Here we have to deal with several serious defects. It could be that piston rings are damaged or cylinder bearing surface.

Blue smoke may be a sign that have used up leak stoppers of valves or turbo-compresor failure.


Black billows of smoke in the diesel engines are not unusual. They may occur when starting the engine or engine subjected to more load.

If black exhaust gases are also visible during easy driving, not with sudden accelerator, it is a signal that  injection system has been deregulation or  failure. You may have to replace the injection pump or injectors themselves. There is also the possibility that damaged the exhaust aftertreatment system. Black smoke may be a sign of a defective turbocompresor or rubber pipe supplying air to the intercooler is leaking.

Rare, with black smoke we have to do in the case of petrol engines. In the case of dark color may indicate problems with the control of the drive unit, for example resulting from not quite professionally made chiptuning. Fuel is too liberally dosed.


Gray, strong-smelling fumes can attest to the fact that the engine receives too rich fuel-air mixture. The fuel can be dosed in too much quantities, for example due to damage to the temperature sensor.


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