White smoke from the exhaust pipe: we understand the reasons
Content
If your car's engine and all systems adjacent to it are in good working order, then the exhaust is nothing more than a mixture of water vapor, nitrogen and carbon dioxide. During the operation of a serviceable unit, a stream of these almost colorless gases flows from the pipe. The catalyst also takes part in the purification, which removes various gases at the outlet of the exhaust manifold.
But sometimes you can notice that white smoke comes out of the muffler. But you don’t need to panic right away, but first of all, you need to take into account several factors that will not indicate a malfunction in the car.
When is white smoke considered normal?
Thick white smoke when the engine is not warm is a normal phenomenon, or rather, in this case, it is not smoke, but steam from boiling moisture from the exhaust system, condensing on cold pipes. As many people know, condensate forms due to temperature differences, and the warm exhaust gas and the cold surface of the metal pipes of the exhaust system are a favorable environment for the formation of condensate. Therefore, this effect should disappear when the engine is fully warmed up. Also, thick white smoke will be emitted even on a warm engine at low ambient temperatures. Starting from frosts of -10 degrees Celsius, the intensity of the rich white exhaust gases will increase with each decrease in air temperature.
When does white smoke from an exhaust pipe indicate a breakdown?
White smoke is a sign of high humidity in the exhaust system. After the engine warms up, steam and condensate disappear. If white smoke still continues to come out of the exhaust, this is a sign of an engine malfunction.
Causes and symptoms of malfunction
Antifreeze leak. If the engine has already warmed up, but white smoke continues to come out of the exhaust, an internal coolant leak may have formed. If there is a sweet smell in the air, this is the most obvious sign of the aforementioned problem.
The reason for this lies in a crack in the cylinder head or even in the engine block. Even if it is small, antifreeze easily leaks out and contaminates the oil in the engine. This causes exhaust smoke to turn white, as the combination of coolant and engine oil gives it a milky appearance. Even a small amount of coolant entering the combustion chamber contributes to the formation of white smoke.
Leakage in the piston ring or valve seal. Another possible cause of white smoke is leaking valve seals or piston rings, which cause oil to leak into the combustion chamber, where it mixes with fuel and burns. As a result, white or slightly bluish smoke comes out of the exhaust manifold.
Faulty injector. If the injector is stuck open or if the O-ring is leaking, too much fuel will enter the combustion chamber. This excess fuel cannot burn properly in the engine and instead exits the exhaust pipe in the form of white or gray smoke.
Incorrect timing of the fuel pump (for vehicles with diesel engines). The diesel engine requires precise synchronization of timing and fuel pressure at the fuel pump. If the timing is not correct, the engine will run at high speed, and this will cause the fuel to not burn completely, but instead will be emitted from the exhaust pipe as white or gray smoke.
What to do if white smoke comes out of the exhaust pipe?
If white smoke continues to come out of the exhaust pipe even after warming up, then an inspection should be carried out.
The first thing to check with constant white smoke is to remove the dipstick and make sure that neither the oil level nor its condition has changed (milky color, emulsion), because the consequences of water entering the oil are the worst for the engine. Also, the exhaust will not emit pure white smoke, but with a bluish tint. This characteristic oil smoke from the exhaust pipe stays behind the car for a long time in the form of fog. And by opening the cap of the expansion tank, you can notice a film of oil on the surface of the coolant and smell the smell of exhaust gases. By the color of soot on the spark plug or its absence, you can also recognize some problems. So, if it looks like new or completely wet, then this indicates water has entered the cylinder.
A white napkin will also help to verify the origin of the smoke. With the engine running, you need to bring it to the exhaust and hold it for a couple of minutes. If the smoke is due to ordinary moisture, then it will be clean, if oil gets into the cylinders, then characteristic greasy spots will remain, and if antifreeze seeps out, then the spots will be bluish or yellow, and with a sour smell. When indirect signs indicated the cause of the appearance of white smoke from the exhaust, then it will be necessary to open the engine and look for a clear defect. Liquid can enter the cylinders either through a damaged gasket or a crack in the block and head.
When looking for cracks, pay special attention to the entire surface of the cylinder head and the block itself, as well as to the inside of the cylinder and the intake and exhaust valve area. With a microcrack, it will not be easy to find a leak, you will need a special pressure test. But if the crack is significant, then continued operation of such a vehicle can lead to water hammer, since fluid can accumulate in the space above the piston.
It may happen that you do not smell exhaust in the radiator, the pressure does not rise sharply in it, but the presence of white smoke, an emulsion, instead of oil, and a drop in its level are noticeable. This indicates the ingress of fluid into the cylinders through the intake system. To determine the reasons for the ingress of water into the cylinders, it is enough to inspect the intake manifold without removing the cylinder head.
Please note that all defects that lead to the formation of white smoke need more than just eliminating the direct causes. These problems are caused by overheating of the engine, and therefore it is imperative to check and repair breakdowns in the cooling system. If you have no experience, then it is better not to try to fix something yourself. Contact a competent specialist so that you do not have to pay twice and fix even more serious problems with the engine after. Employees at the service station will immediately diagnose you, identify problems and fix them.
White smoke from the exhaust pipe is not necessarily the cause of serious problems, but it does not hurt to check again and make sure that everything is in order with the machine. Therefore, it will never be superfluous to contact a good service station, where experienced craftsmen can quickly and accurately diagnose all nodes. Also, as practice shows, an experienced craftsman with all the necessary tools and the right equipment will cope with this problem many times faster than one person in simple garage conditions.
