I get asked a lot about car exhaust. Often, beginners, and even experienced drivers, do not like how the car “smokes”. Or rather, sometimes from the exhaust pipe goes white smoke can appear both in the morning (when the engine is just started) and during the day. And there are two different reasons. But everything is in order ...
What is an exhaust?
If your power unit and the systems adjacent to it are serviceable and operating normally, then the exhaust is nothing more than a combination of water vapor, nitrogen and carbon dioxide. They are practically colorless, during the operation of a working unit, an invisible stream of these gases comes out of the pipe, it also works in purification, and which removes various gases at the outlet of the exhaust manifold.
But why does white smoke sometimes come out of the muffler? It manifests itself especially in the morning in cold weather? It's not always a malfunction, it's simple physics.
Cold weather
The first reason for this phenomenon may be cold weather. As we explained above, there is water vapor in the exhaust, there is no hiding from this, because it is in the air that is sucked in by the engine to create fuel mixture. In cold weather, hot steam comes out of the muffler, cooling instantly, here you have a whitish tint - or rather steam! Moreover, the lower the temperature, the stronger it will be noticeable. It's like steam coming out of your mouth.
I would also like to note that sometimes condensation forms in the muffler due to temperature differences. And when you start the engine, the muffler heats up, and the water begins to evaporate. Thus, even in warm weather, white smoke can come out.
Condensation forms in exhaust pipe due to frequent short runs, for example, you live close to work. The exhaust system does not have time to warm up to evaporate all the water, and when it cools down, evaporation does not occur. Thus, the water level is rising, I personally saw it when they poured about a liter. In order for it to evaporate and not form again, you need to drive at least once a week for long distances, from 30 minutes or more. Or just warm up the car in the yard, then the concentration of "steam" will decrease significantly.
As you understand, this is not a fatal cause, it does not indicate a breakdown. But there is also one in which there is a very serious damage systems.
Breaking
Usually the symptoms are: - no matter what the weather and temperature, warm or not the engine, very thick comes out of the exhaust pipe white exhaust, and the coolant level is constantly falling (how can you find out), you add a new batch of liquid almost every day. Turnovers constantly "dance", from 800 to 1200.
I'll tell you guys right away - nothing good. You need to go to the service station and the sooner the better. If you stretch it, you can ruin your unit, here it’s not far to “”.
Reason: — The whole point is that the coolant enters the combustion chamber, after which it exits the muffler with the exhaust. This is very dangerous, because there is also mixing with oil, its properties are falling, after fixing the problem, it is advisable to change it.
Why is this happening? And how can she get there?
It's all about the design of the engine. As you know, it consists of a block and an upper head (where the “camshaft” is located), there is a gasket between them, the design must be tight - since coolant circulates in the block and the “head”, which removes excessive overheating. It should be noted that the liquid also passes through the gasket (there are special grooves there).
If everything is normal, there are no leaks - antifreeze cannot get into the cylinders. But if the head of the block is improperly mounted (poorly twisted) or if it is damaged, small deflections are possible through which liquid begins to ooze. It is she who enters the combustion chambers, immediately evaporating and turning into a thick white vapor.
Therefore, you need to clearly know what is happening with your engine - the usual steam or all the antifreeze is leaving. Watch a helpful video.
You can diagnose the breakdown yourself, there is one "old-fashioned" method.
1) We warm up the engine to operating temperature, it would be nice after a short run.
2) We take a blank piece of paper and apply it to the exhaust pipe. Not covering it completely, about half. Hold for 10 - 15 seconds.
3) We look at the paper, if it is wet as from water, there is nothing to worry about. It's just water. If the paper is oily, as after oil, this is bad! So, antifreeze or antifreeze goes into your system. You need to go to the service station, do not delay.
Let's watch a short video.
Filters
You know the last reason, there may be failed (clogged) engine filters for air purification. I also thought that this is not possible - but it's a fact! The thing is that there is less air (dirty filters do not allow it to pass), but there is more fuel, while the “smoke” increases. But here it can also show not only white but also black exhaust. But this is a topic for another article, be sure to follow our blog.
In the end, I want to say - if you have such a “whitish fog” effect in winter, the liquid level does not drop, then this is normal! You shouldn't even pay attention to it.
Owners personal transport over time, they face the problem “Why is the engine smoking?” and “Do I need to do something urgently?”. There is no single answer. There are 3 types of exhaust smoke.
Its occurrence is associated primarily with the formation of condensate. Often . If this phenomenon occurs in winter or at high humidity, then the owner should not worry - this is the steam formed during heating.
The reason for the appearance of such smoke on a warm engine may be the ingress of antifreeze into the block. But there is feature- a specific smell of smoke, you can’t confuse it with anything, very unpleasant. The ingress of antifreeze into the cylinders disrupts the working processes and leads to a violation of the cleanliness of the surface of the cylinders and an increase in the wear of the main parts. It is impossible to ignore such a defect!
Black smoke
Black color exhaust gases car
Its appearance is associated with enriched fuel-air mixture, i.e. the amount of gasoline exceeds the calculated one. This leads to the washing of oil from the cylinder walls by gasoline and, as a result, the failure of the cylinder-piston pair. It is also possible that the engine will be subjected to water hammer.
The main companion of black exhaust is increased gas mileage. The reasons that the engine smokes may be malfunctions of the fuel supply, ignition or injection control systems.
gray smoke
If water and gasoline were the causes of white and black smoke, then oil is the cause. If you doubt the color of the smoke, then whether it was "oily" can be determined by the condition of the exhaust pipe. IN this case she will be fat. A faithful companion of gray smoke is increased consumption oils.
Why does the engine smoke and consume oil?
This is due to oil entering the combustion chamber either through the piston lubrication system or from the valve side. If it's due to wear and tear cylinder-piston group, then you will have to resort to switching to the repair size of the piston and honing the cylinders. If the cause is in the valves, then their caps will have to be replaced. In turbocharged engines, oil can leak from the turbocharger seals.
But what if the engine eats oil but doesn't smoke?
Then this is a banal leak. Visually inspect the parking lot of the car, if it didn’t tell you anything, then this is not a gearbox. Inspect the engine in the area of the gaskets of the valve cover, pan. And everything is clean there? Then the reason may be in the seals on the crankshaft or in the seals on the distributor.
Smoke additives
Engine additives
Additives are aimed at increasing wear resistance, reducing friction, and increasing compression. All this is achieved due to the sticking of the film in defective areas of rubbing surfaces. If you have smoke due to minor wear piston-cylinder group, then finally, of course, it will not save, but as a temporary solution it will work.
The use of additives can be an option for a temporary solution to the problem.
And if your cause of smoke is, for example, a sensor failure, then no oil additives, alas, will help you.
Thus, the use of additives will not free you from constant control for his vehicle and from periodic diagnosis of his condition.
A diesel engine can emit white, blue and black smoke from the exhaust pipe, as well as numerous shades of these colors that are clearly visible in the exhaust. If the diesel smokes blue or gray smoke “cold” and / or “hot”, then a malfunction is quite obvious. power unit. The appearance of blue diesel exhaust often indicates two problems:
- violation of the efficiency of fuel spraying;
- into cylinders diesel engine engine oil gets in;
Read in this article
Diagnosis and localization of the problem
In the first case, the exhaust is blue, caustic, has a pungent odor. The reason is that only well atomized diesel fuel burns in the cylinder. Drops of unburned diesel fuel fly out of the exhaust pipe in a vapor state. Another part of the drops burns inside the cylinder, but already on the piston itself. This causes severe overheating, which can lead to melting or burnout.
In the second case, the exhaust takes on a whitish-blue to dark blue color. The color of the exhaust directly depends on the amount of oil penetrating into the combustion chamber, the mode of operation and the degree of warming up of the engine. Exhaust smell from big amount oil is burnt, such smoke in the air dissipates for a long time.
Distinguish white-blue smoke with impurities burnt oil from water vapor in the exhaust will help the following method. It is enough to attach a sheet of white paper to the exhaust pipe of a warm diesel engine. As a result, spots will appear on the paper. If the spots are from water, then they evaporate, leaving no obvious traces on the sheet. Grease stains will indicate the presence of oil in exhaust gases engine.
The appearance of oil smoke is accompanied by an increase in consumption engine oil. During ICE operation in transient conditions, smoke with impurities of burnt oil is thicker. Catalyst ( catalytic converter) gasoline engines cleans the exhaust of oil even when it big expense. On diesel internal combustion engines oil exhaust is more noticeable.
Blue smoke: wear of the cylinder-piston group
Most common cause the fact that the diesel smokes blue smoke is the wear and tear of the parts. Oil entering the combustion chamber can occur due to an increase in the gaps of the piston rings, the gaps between the rods and the guide bushings. Damage may be on the cylinder liner, destruction of rings, piston grooves, etc. is possible.
The presence of strong gaps in the area of the piston grooves cause the oil to be "sucked" into the combustion chamber. This happens even considering the normal state oil scraper rings. Additionally, the shape of the cylinder can be changed, which significantly reduces the sealing by means of the rings. Cylinders may become elliptical, resulting in gaps. CPG wear causes loss of compression, pressure also rises crankcase gases. When measuring compression, it must be taken into account that the oil in the cylinders can seal the gaps. It turns out that the compression bad cylinder will be overstated. To obtain accurate compression and CPG condition assessment results, a number of specific requirements must be met.
If the CPG is not worn out much, then blue smoke is clearly visible during the engine warm-up. After leaving for operating temperature the intensity of smoke decreases or the blue diesel smoke disappears completely. This is due to the expansion of parts as a result of heating, which causes the sealing of gaps. An example is that a diesel engine does not start well “cold”, but a repeated hot start occurs without problems.
Strong wear of the CPG causes more active smoke generation "on hot". The heated oil becomes less viscous and easily gets into internal combustion engine cylinders, and the thermal expansion of the parts of the cylinder-piston group is no longer able to compensate for too large gaps.
Oil consumption increases as a result of breakage of the bridges between the piston grooves. An increase in engine oil consumption is caused by broken rings as a result of wear or overheating of the diesel engine. The use of low quality oil and its untimely replacement leads to the occurrence of piston rings. The rings "stick" in the piston grooves, and their mobility is completely lost.
Detect oil ingress into cylinders due to CPG wear help direct (overspending of oil) and indirect signs. The second group includes: the appearance of noise from the operation of the motor, various knocks appear with a change in speed and load on the engine, the intensity of smoke with blue or gray smoke changes as the engine warms up, noticeable unstable work diesel at cold start.
Timing malfunctions and other causes of blue exhaust
Oil smoke and increased oil consumption can also be related to the timing:
- burnout or destruction of the valve disc;
- wear of valve stems and guide bushings;
- there are defects in the valve stem seals;
The answer to the question of why a diesel smokes blue smoke after warming up can be based on oil dilution after growth. internal combustion engine temperature. During the operation of the motor idling and at the moment of engine braking, oil flows down the valve stems, a film forms on the parts, and its accumulation in the exhaust system is observed. When the driver presses on the gas, a thick cloud of blue oily exhaust abruptly emerges from the exhaust pipe.
Black diesel exhaust. Soot from the exhaust pipe of a diesel engine, the cause of incomplete combustion of fuel. Identification of major faults.
If the engine is gasoline, then its normal condition is determined by the almost complete absence of smoke. Although it should be noted that there are still some exceptions. It lies in the physical aspect of gasoline, which, when burned, produces water, which in turn can lead to white smoke, which will be water vapor.
It is also worth mentioning that only the color of the smoke does not characterize the problem of the engine, in addition, it is necessary to look for other deviations in the work. The set of failures in the operation of your car is an indicator of a problem that needs to be identified and resolved.
Causes of smoke
Let's try to answer the question: why does the car smoke? We will also find out how much the color of the smoke allows us to characterize the problem.
- White smoke. Smoke white color mostly not a sign of problems in the operation of the car engine. Basically, such smoke can be seen during warm-up. As already mentioned, this is not smoke, but water vapor, which acts as a product of combustion. That is, a few minutes and the smoke disappears - this is a good sign. If the process of smoking continues during your movement, then you should think about it.
For example, there may be an option that the gasket, which is located on the cylinder head, has leaked, which allows the coolant to enter directly into the cylinders. Usually education white smoke associated with elementary overheating of the power unit. Therefore, it is worth checking the operation of the thermostat, as well as the integrity of the radiator and hoses.
- Black smoke . This shade of smoke indicates that the power supply system of the power unit is junk and does not properly mix fuel with air. Of course, the problem can be somewhat banal, and is related to the quality of the fuel, or rather, its poor quality. But incorrect mixture formation is still the most common phenomenon, that is, the process is caused by an excess of fuel or a lack of air.
Lack of air can be formed due to clogging air filter or air ducts, and may also be observed wrong job air flow sensor. If the amount of smoke increases by high revs then check the fuel pressure. If black smoke is observed from a machine equipped with diesel unit, check the operation of the high pressure pump.
- blue smoke. Blue smoke is caused by oil entering the combustion chamber. In this case, the smoke may have a fairly light tint and can be confused with white smoke. There is a method that allows you to determine the nature of the smoke. To do this, you need to attach a sheet of paper to the exhaust pipe, if greasy drops are visible on the paper, then the problem is with the oil. The ingress of oil into the combustion chamber is determined by malfunctions in the cylinder-piston group.
Part wear
These malfunctions may occur due to wear of parts, as well as inner part cylinders can be corroded if the car has not been used for its intended purpose for a long time. When the wear of parts is minimal, then smoke occurs only during start-up, and after warming up, the smoke disappears. In addition, it is possible mechanical damage, for example, a skewed connecting rod.
Exhaust discoloration is a warning sign. It is necessary to find out the reasons why the engine smokes with blue smoke as soon as possible, since this phenomenon indicates that oil enters the engine cylinders. No wonder among drivers such an exhaust is called oil. Its color can take on different shades and have different saturation.
The range includes almost the entire blue palette, from transparent blue to deep blue. On appearance smoke is influenced by many factors: the degree of warming up of the engine, its mode of operation, even the illumination of the place where you paid attention to the exhaust of your car.
Combines all variations of oil smoke 2 signs:
- Firstly, it does not dissipate, but rather stays on for a long time in the air.
- Secondly, if you bring a clean piece of paper to the exhaust pipe, after drying, a distinct oily stain remains on it.
When to worry
It's not always oil smoke that pushes you in the direction of the auto repair shop. You can take a closer look, listen and draw the appropriate conclusions, but you can take your time with an accurate diagnosis in 2 cases:
- new (or almost new) car (read how to do it right);
When is it time to take action?
It is quite another matter if, according to the degree of warming up of the engine, the smoke intensifies. This is easily explained: the fluidity of the heated oil increases, and it more intensively penetrates into the defects that have appeared. At the same time, oil exhaust is accompanied by an increase in oil consumption, so you can also guess about creeping problems from the readings of the relevant instruments.
Moreover, you can even approximately estimate the degree of threat: if the consumption has increased to 0.5 liters per 100 km and blue smoke begins to appear mainly in transient conditions, you still have some time to solve the problem at the lowest cost.
If about a liter of oil is consumed per 100 km, the engine smokes even with uniform operation, and when the speed increases, the oil exhaust becomes blue-white, a trip to the service station has become very urgent.
Those who have the most modern models: the neutralizers standing on them can significantly clean the exhaust gases, and the visual alarm signal is very weak. Here, control will have to be carried out according to the values \u200b\u200bof oil consumption.
Most often the phenomenon is caused by problems with piston rings. They can wear out both on the outside and on the ends.
If the rings themselves do not show signs of wear, oil leakage may occur along worn grooves on the rings.
Next possible reason –cylinder wear. Most of all, their highest point suffers from it, where the ring stops during operation when the piston reaches the top dead zone. During the cylinder check, its geometry is measured, since even a small deviation in dimension leads to a deterioration in tightness, and, consequently, to oil suction.
The reason for the appearance of blue smoke may be. An indirect sign of this is the bluish tint of the exhaust. You can check the assumption even without visiting a car repair shop: you need to unscrew the candles and measure the compression in the cylinders. In the victim, it will be absent, and thick black soot will appear on the candle. If you have been driving with such a cylinder for more than one day, instead of soot, there will be a tar-oil coating.
Wear of bushings, valve stems and oil removal caps can be combined into a separate group.
On turbocharged engines gray exhaust often associated with malfunctions of the turbocharger, with the development of bearings, rotor seals. The same picture is obtained when the caps fail; the difference is the formation of an oil puddle on the inlet compressor pipe.
Here are the main reasons why the engine smokes with bluish smoke, however, it also happens to be completely exotic, such as a rupture of the regulator membrane on a car with an automatic transmission with a vacuum sensor. If you not professional auto mechanic, you may not be able to figure out what you're up against. So your task when detecting oil exhaust is to get to the service station as soon as possible.
