Causes of white smoke from the exhaust pipe

On Soviet cars, experienced mechanics could accurately determine the cause of the appearance of white exhaust gases from the car's exhaust pipe. On modern imported vehicles, the design of the exhaust system is somewhat more complicated, therefore, minders can determine some of the causes of white smoke from the exhaust pipe visually (based on experience), and to identify other factors for the appearance of white gases from the exhaust pipe, they need to use modern diagnostic equipment.

The device of the exhaust system of modern cars

Modern vehicles are equipped with a more sophisticated exhaust system that traps most harmful substances:

Exhaust system device

• Exhaust manifold - combines exhaust gases from all cylinders into one stream;
• Catalyst. Introduced into the system relatively recently, it consists of a special filter that traps harmful substances and a sensor that controls the level of gas purification. On cheaper car models, a flame arrester can be used instead of a catalyst, which reduces the cost of the vehicle;
• Resonator. In this element of the exhaust system, gases reduce their temperature and noise level;
• Muffler. The very name of the system element speaks of its purpose - to reduce the noise level emitted by the vehicle to the maximum permissible limit.

Causes of white smoke from the exhaust pipe

The factors by which white smoke comes out of the exhaust pipe can be insignificant and significant, which can affect the comfort and safety of movement of the driver and passengers.

white smoke from the tailpipe causes

Reasons not requiring repair

Minor factors that cause white smoke to come out of the exhaust pipe:

• In winter, a temperature drop occurs in the exhaust system, resulting in white smoke. After the engine has been running for a while, the smoke should disappear;
• Condensation has accumulated in the system; after a while after the engine is running, white smoke will pass. When the engine has warmed up, and the smoke does not pass, then you need to go to a good minder so that he can determine the cause of the malfunction.

The above two reasons for the appearance of white smoke from the exhaust pipe are not malfunctions, but only temporary phenomena.

 

How to independently check the nature of the exhaust gases

The vehicle owner needs to learn to distinguish between water vapor and bluish smoke from burning engine oil. You can also check the structure of the smoke by placing a blank sheet of paper under the exhaust gases. If oil spots appear on it, the oil scraper rings have become unusable and you need to think about overhauling the engine. If there are no oil stains on the sheet of paper, then the smoke is simply evaporating condensate.

Reasons for requiring engine repair

Significant reasons why white smoke can come out of the exhaust pipe:

• Oil scraper rings allow oil to pass through. We described this case above;
• Coolant enters the exhaust system. If white smoke from the exhaust pipe does not pass for a long time in a warm time of the day or on a well-heated engine, then it is possible that the coolant has begun to penetrate into the cylinders.

This malfunction is detected in several ways:

• a clean sheet of paper is brought to the pipe and if there are greasy stains on it, you need to go to a good minder;
• the car enthusiast notices that the antifreeze in the tank began to constantly decrease;
• at idle, the power unit runs unevenly (idle increases and decreases).

How to check the ingress of coolant into the cylinders

• Raise the hood and unscrew the plug on the expansion tank;
• Start the power unit;
• Look inside the tank and try to find greasy stains on the surface of the coolant. If oil stains are visible on the surface of antifreeze or antifreeze, and a characteristic smell of exhaust gases comes from the tank, it means that the gasket under the cylinder head is broken or a crack has formed in one of the cylinders.

Cylinder block gasket - cause of white smoke

With such a malfunction, a certain amount of coolant will regularly enter the oil pan.

In this case, the pressure in the engine cooling system will increase due to gases that come from the cylinders.
You can identify such a malfunction by checking the engine oil level. With such a problem, the oil on the dipstick will be slightly lighter than when the coolant does not enter the crankcase of the power unit. It is clear that in this case, the lubrication of the metal parts of the engine will be of poor quality and this can lead to the fact that the power unit will jam.

When some of the coolant enters the oil pan, white smoke will come out of the exhaust pipe until the powertrain malfunction is repaired. It will be superfluous to remind motorists that after eliminating a malfunction in which antifreeze enters the crankcase, it is necessary to fill in new engine oil.

How the malfunction of coolant entering the cylinders is eliminated

Elimination of a malfunction in the power unit, in which coolant enters the engine crankcase:

Most likely: The cylinder head gasket (cylinder head) is punctured. It is necessary to dismantle the head and replace the gasket with a new one.

A motorist can eliminate this malfunction himself, only it is necessary to know in what order the nuts on the cylinder head are pulled, and you must have a dynamometer, since this operation is performed with a certain effort.

The cylinder itself is damaged, for example, a crack has appeared. This problem simply cannot be solved, most likely you will have to change the block.

Therefore, keeping in mind the axiom of life: there is nothing worse than remodeling something for someone, we recommend finding a good minder and let a professional diagnose the engine. After all, a high-quality repair of a power unit depends on a professional determination of the cause of a malfunction - this is an axiom. And from the one who does the repair.

We hope that the information about the causes of white smoke from the exhaust pipe, which we have shared in this article, will help motorists keep their "iron horses" safe and sound. And if the malfunction has already happened, then you already know the correct behavior algorithm in order for the vehicle to serve for a long time and efficiently.

Questions and answers:

What kind of smoke should come out of the exhaust pipe? It depends on the ambient temperature. In the cold, white smoke is the norm, because it contains water vapor. After warming up, the smoke should disappear as much as possible.

What does white smoke in a diesel mean? While the diesel unit is warming up, this is the norm, as for a gasoline engine (condensate evaporates). On an ongoing basis, the engine smokes due to antifreeze leakage, incomplete fuel combustion.