Newbie drivers often look for the answer to the question of why the VAZ smokes. There are several reasons that can cause copious emission of thick smoke-like vapor. But there are also breakdowns that are accompanied by smoke. What to do when the car began to smoke?
VAZ cars have many different problems, including the frequent presence of exhaust system and engine malfunctions. Most malfunctions of the ignition system, exhaust system and engine assembly are accompanied by smoke. This happens according to different reasons. First you need to sort out all the options when you should not worry about the integrity of any of the systems.
Here is the first and main one: the engine starts, the abundant release of white smoke from the exhaust pipe begins.
This is quite normal. The white color of the vaporous substance indicates that the mechanisms of the car began to work with a large temperature difference between cold parts and the environment. This usually happens after a long period of inactivity. When the engine starts, all internal systems are immediately heated, with steam, which is usually not visible, being released in huge quantities due to a sharp change temperature regime. Many beginners may be intimidated by the large cloud that forms from the exhaust after starting the engine.
But this does not portend trouble if an increase in fuel, oil or cooling fluid consumption has not been noticed. Particularly thick vaporization occurs after cold winters and long machine downtime without work.
White vapor is not dangerous, so there is no cause for concern.
blue smoke
Smoke of any other color is a sign of a rather serious breakdown. One of the signs of damage is bluish smoke that appears after starting the engine. It can have all shades of color up to dark blue, which will mean extensive damage. piston system car. If bluish smoke comes out of the exhaust pipe, some part of the cylinder is broken. Why is this happening?
Oil must flow into the cylinders to lubricate the mechanisms, partially cool them and improve their working condition. Normally, oil cannot get into other components, but if any part of the piston or oil distribution system has been damaged, it will leak into the engine chamber. The coolant washes away the oil, taking it with it into the cooling system, where it evaporates into the exhaust ducts. Because of this, the smoke gets a bluish color. The color will depend on the intensity of the engine - from transparent blue, almost white to almost blue.
Gas formation of this color is accompanied by a strong consumption of oil. The solution to the problem is to check the piston lubrication system, valve stem seals Or change the oil to a different brand.
Such smoke in the VAZ-2105 can also appear from the side of the carburetor, not only in the exhaust. It can also be due to a long period of inactivity of the car or damage to the system. If the color of the smoke changes over time, then there is no need to worry, the leak goes away after the parts warm up.
Black smoke
One of the most dangerous species breakdowns are malfunctions of the engine and fuel system, which are accompanied by black smoke from the exhaust pipe.
Here are other signs that may appear with this:
- Fuel consumption increases significantly, the smoke is very thick and dark, therefore quite toxic.
- The engine is unstable, sometimes stalls.
- There is a loss of engine power.
- The engine starts very badly.
Why is this happening? For VAZ, this malfunction is characteristic due to the presence of a carburetor. A faulty needle valve causes overflow in the float chamber. This problem also happens when the air jets are clogged. It is worth cleaning them and replacing parts, adjusting the fuel supply system or the entire engine.
Other sources of smoke
Exists whole line other problems that cause smoke from the engine side:
- Cooling system failure. Parts overheat and partially burn, smoke is emitted.
- Breakdown of the fuel supply system. In addition, the fuel may not burn completely, resulting in exhaust gases of a different color.
- Coolant or oil enters the engine cylinders due to damage in them.
It is impossible to list all the possible problems that may cause smoke to be emitted from the machine. Basically, replacing parts, oil or fuel is enough to fix the problem, but sometimes the cause of the breakdown cannot be found out on your own.
In this case the only option- a trip to a car service complex diagnostics and repair.
A familiar picture: they started the engine after long parking and from the exhaust pipe
poured thick smoke. It is quite possible that after warming up it will decrease, and when traveling at all
will disappear. But more often it is different. The smoke continues and clearly shows that in the motor
there are some problems. Long inaction served as a kind of impetus for their
to whom manifestation.
Exhaust smoke can be white, black, or anything in between. Color
serves as an important diagnostic feature. Engine operation with increased smoke often
accompanied by other deviations from the norm, although sometimes subtle. They are sure
it is necessary to catch and mark in order to more accurately assess the situation.
Typically, the appearance of smoke is associated with malfunctions of the following operating
engine parts: control systems (mainly fuel supply),
cooling system, mechanical part (piston group,
distribution mechanism, etc.). Accordingly, the smoke arises
either due to incomplete or "improper" combustion of the fuel, or
coolant entering the cylinders, or oil entering there.
Presence of oil, coolant, or excess fuel when
combustion in the cylinders and imparts the characteristic color exhaust gases.
If we analyze possible faults, then it turns out that
in many situations, the smoke is the same color, although it has a different nature.
Another circumstance:
often a malfunction of one system, which turns out to be a source of smoke,
occurs due to malfunctions and defects in the other. Here is a typical example:
bad job cooling system causes the engine to overheat and,
respectively, the burning of piston rings. Already as a result of this
oil enters the cylinders and causes smoke, which is caused by
essentially secondary.
It is better to start searching for the cause of smoke by comparing all the recorded circumstances:
the nature of the smoke itself, the observed accompanying phenomena, possible external influences.
We will talk about the characteristic combinations of these factors.
White smoke.
White smoke from the exhaust pipe is quite normal for warm-up cold modes.
engine. It's not just smoke, it's steam. Water in the vapor state is a natural product of the
fuel wound. In an unheated exhaust system, this vapor partially condenses and becomes
visible, and water usually appears on the cut of the exhaust pipe. As the system warms up, condensation decreases. The colder environment, the more dense and white
steam is obtained. At temperatures below -10 ° C, white vapor is also formed on a well-heated engine
body, and when frost is minus 20-25 degrees, it acquires a thick white color with a bluish tint. On
the color and saturation of the steam is also affected by the humidity of the air: the higher it is, the thicker the steam.
White smoke in warm weather and on a well-warmed engine is most often associated with
coolant into the cylinders (for example, through a leaky head gasket),
The water contained in the coolant does not have time to completely evaporate during combustion
fuel and forms a fairly thick white smoke (in fact, again, steam). Its shade depends on
composition of the coolant, weather and light outside. Sometimes he looks blue
reminiscent of "oil" smoke. Distinguishing water vapor is easy: it immediately dissipates, and after "oil-
a bluish fog remains in the air for a long time.
To make sure that the cooling system is at fault, a series of targeted checks will be required. It is easy to clarify that water is indeed emitted from the exhaust pipe, and not oil.
To do this, on a well-heated engine, briefly close the exhaust pipe opening
sheet of paper. Drops of water from the leaf will gradually evaporate and will not leave obvious greasy marks, and
to the touch they will not be greasy.
Further, the search must be coordinated with the design of the engine. Fluid can enter the cylinder
due not only to gasket damage, but also to cracks in the cylinder head or block. All
these defects during engine operation cause hit exhaust gases into the cooling system
(sometimes a gas plug is even formed there), which serves as the basis for recognition.
By opening the cap of the radiator or expansion tank, it is easy to notice the smell of exhaust gases and
film of oil on the surface of the coolant. And the liquid level will be lowered-
nym. It is characteristic that in such cases, after starting a cold engine, the pressure in the system
cooling rises immediately (it is easy to feel with your hand by squeezing the upper radiator hose), quickly
the liquid level in the expansion tank also increases. Moreover, this level is unstable, and in
reservoir, you can notice the release of gas bubbles, sometimes with a periodic release of coolant
bones from a jar.
Didn't find an answer? Free legal advice!
Or call the numbers below: It's fast and free!Periodically, any engine (even a new one) smokes, so every car owner sooner or later asks himself the question - “why does the engine smoke?”.
There is an opinion among motorists that the color of the smoke from the exhaust pipe can determine what kind of engine malfunction it is caused by. Let's first consider this issue in in general terms, and then we will analyze each specific case in more detail and make this visual malfunction point us to more serious defects hidden from our eyes, i.e. by the color of the exhaust, we determine the state of the car's engine. In general terms, the question of why the car smokes can be answered as follows:1) Whitish / clear smoke from the exhaust - water from the muffler
during operation of a cold engine or during operation in the cold season - this is normal. The oxidation of any carbon fuel ideally yields CO2 and H2O. If CO2 exits the engine in the form of a transparent gas, then H2O exits as superheated vapor and, as it cools, turns into a liquid state. It is the condensed water vapors that we observe in the form of smoke from the exhaust pipe. The fact that water vapors are always present in the exhaust (even when they are transparent and we do not see them) is quite easy to verify by simple experience: cool the saucepan (or any other utensil) and place under the exhaust pipe of a running engine.
And you will be able to observe how steam from the exhaust gases will condense on the cold walls. At the beginning of the engine, while both it and exhaust system not warmed up, you can even watch how it drips from the muffler. In this case, the exhaust system itself plays the role of cold dishes.
It should be noted that water vapor after exiting the exhaust pipe dissipates rather quickly and does not smell of anything.
2) Black smoke from the exhaust pipe
similar to what is spewed from their bowels by loaded old trucks going uphill (I think this picture is familiar to everyone) is the brainchild of soot. cars Black smoke from the exhaust pipe appears mainly during a sharp increase in load, or when driving with a high load. Even logically, it can be determined that the reason for it is poor carburetion (over-fueled mixture). Like any deviation in mixture formation, this leads to excessive fuel consumption. Well, it is also necessary to repair the fuel equipment or the engine control system, respectively.Here we can draw an analogy with two-stroke motorcycles– everyone has seen what happens when a motorcyclist adds excess amount oil into fuel (those who have not seen a motorcycle may remember a chainsaw, or another device with a two-stroke engine), the exhaust in this case smells like burnt oil. Thick clouds of bluish engine smoke flying out of the exhaust pipe, and dissipating for quite some time. The same is true in a car, in the cylinders of which, for some reason, excess oil enters. Of course, the density and amount of smoke strongly depends on the operating mode of the engine, as well as on the degree of warming up, downtime and other factors.
The degree of bluishness of this smoke, it should be noted, is quite weak, it is somewhat similar to an ordinary park, but the smell of oil and traces on white paper (+ oil consumption) should help you orient yourself.
In this case, you need to look at the engine hardware itself.
4) White smoke from the exhaust pipe - water from the muffler
A case similar to that described in the first paragraph, but thicker and not disappearing completely when the engine warms up in the warm season.
In addition to oil, coolant can also enter the engine cylinders. It is she who, condensing, turns into white vapor, which dissipates relatively quickly in the air. But there is a small but: liquids of various properties and structure are used as a cooling liquid. For this reason, steam may differ from pure white color and thus mislead the owner. For greater certainty, you need to pay attention to the flow of coolant. The hardware of the engine and the cooling system are subject to repair.
If we consider the essence of this problem in more detail, it turns out that in real life not everything is so clear. Usually, an engine malfunction is complex, and it is all the more frivolous to start a repair based only on the color of the smoke from the exhaust pipe without checking your assumptions with additional methods.
For a fairly accurate diagnosis of the condition of the engine, you will have to roll up your sleeves and conduct more complex diagnostics.
1) Transparent steam.
It does not require explanations and repairs, it is only worth noting - be careful when you put the car on automatic winding in winter due to temperature - it can simply clog the exhaust pipe with ice and the car will not start.
As a rule, soaring appears either in the cold season or in wet weather. The dynamics are as follows: when you start the engine, you can see a barely noticeable soaring, as it warms up, soaring intensifies. When driving with a cold engine, droplets of liquid may drip from the exhaust pipe. As a rule, by the time the engine is fully warmed up, the soaring either completely disappears or decreases. It should be borne in mind that not only working temperature engine matters, but so does the temperature of the entire exhaust system.
2) Black smoke from the exhaust
as a rule, is the cause of a lack of air (or an excess of fuel). Accordingly, the solution to the problem based on this:
The most shameful case is a clogged air filter (especially detrimental to carburetor, gas and diesel engines).
Next, you need to look at the compression - with “leaky” cylinders, the combustion process deviates from the calculated one and does not bring the proper result (the required power), as a result of which the ECU can re-enrich the mixture, regardless of its full serviceability.
We look at the fuel pressure and fuel correction - a situation is possible when a contaminated fuel system and the fuel pressure is low, which leads to a long and not timely injection of fuel into the cylinders. Or a variant is possible when the nozzles do not close completely and “pour” which leads to very poor low flow fuel, reduced power, and sometimes even water hammer (fuel accumulated in the manifold flows into the cylinder and leads to breakdown).
Sensors for monitoring the operation of the engine can also give erroneous readings, resulting in the operation of the ECU “blindly”. As a rule, in this case, the check engine light comes on ( check engine) . However, in some models, this light does not always light up if there is a malfunction of any engine. You can read more about engine management systems here.
All the described cases are accompanied by the formation of black soot on spark plugs, increased fuel consumption, reduced engine performance, increased wear of the CPG (gasoline washes away the oil film from the cylinders), shots in the muffler are possible and often there is a smell of gasoline from the smoke from the exhaust pipe.
Spark plugs can help diagnose the problem. With black smoke from the exhaust pipe, as a rule, candles have a soot-black coating.
That is, when analyzing smoke from the exhaust pipe, it is desirable to analyze the condition of the candles.
In any case, driving this way is not only not environmentally friendly, but also expensive, measures must be taken.
3) Bluish smoke from the exhaust pipe.
The most typical situation that I have encountered on some of my cars is puffs of smoke in the first 10-30 seconds after starting the engine. The defect progresses with increasing mileage and with a decrease in outside temperature. You start the engine and see a cloud of bluish oil smoke in the rearview mirror. You, of course, tense up, bad thoughts about expensive repairs come to your head. But at the end of the journey, everything becomes normal. Of course, repairs are delayed.
As mentioned earlier, the reason is a large amount of oil that has entered the cylinders or the exhaust tract. In our case, oil enters the cylinders during the parking period through loose (hardened) valve stem seals. At this point, you will most likely have a little difficulty starting the engine due to oil deposits on the spark plug electrodes.
But blue smoke can appear not only after a cold start of the engine, but also while driving. Moreover, it happens that smoke appears at the moment of coasting (when throttle valve closed) or under load, etc. If smoke appears when coasting, the reason for this will be the CPG: at this moment, a vacuum forms in the cylinders and, through a loose friction pair, the piston ring cylinder oil mist from the crankcase is sucked into the hot cylinder
The most common causes of blue smoke are described below:
a) Worn or hardened valve stem seals.
The malfunction is gradually increasing and manifests itself in the form of a large emission of smoke at the first moment after cranking, then gradually the intensity of the smoke decreases (as it warms up). This is due to the softening of the caps as they warm up. Accelerated wear of the caps may be an increased clearance in the valve bushings, low quality caps or a large number crankcase gases(due to CPG wear).
Of great importance is the quality of the valve stem seals themselves. Unfortunately, this is what I came across:
The photo shows two different caps working in the same conditions. And if the left cap is already hardened (the car was shamelessly smoking and eating about a liter of oil per 1000 km), then the right one looks like new after 50k. work. The name of the good one is RoadSafe, and the name of the bad one is incognito, because most likely it is counterfeit and cast a shadow on brand Mitsubishi I do not want.
In this case, the oil will enter through the leaky connection of the clan with the seat (sealed by MSC). And it will fall both into the intake (if the valve is closed at the time of parking), and into the cylinder (if the valve is open) or even into exhaust manifold through the exhaust valve bushings. Abundant smoke in the first moments will be caused by the combustion of all the oil that has drained into the cylinders from the block head during the idle time and the low elasticity of the cold rubber of the valve stem seals.
b) Wear or occurrence of oil scraper rings.
In this case, the oil film is not removed by specially designed rings and oil enters the cylinders in an excessive volume. Perhaps this is the reason why the engine can eat the largest number oils. At the first stage, decarbonization of the rings can help. But after that, it is necessary to increase attention to the engine, because. this may mean the loss of spring properties of the rings and a quick re-occurrence. The method for checking piston rings is described on the page on measuring compression in the engine, so I will not repeat it.
I will only add that the diagnosis is difficult if only the oil scraper (lower) rings are stuck. compression is nominal at the same time, and decarbonization does not help due to good condition top rings. Similar option in the photo below:
c) Turbine failure.
Cars equipped with turbochargers in a deplorable state of the latter can smoke due to oil being thrown by the turbine. In this case, the oil used to lubricate the turbine bearings, through faulty seals (usually turbine shaft seals), is thrown into the intake tract:
This is pretty easy to diagnose. It is enough to remove the air duct going from the turbine to the engine at the lowest point and look to see if there is oil inside. Or (in the early stages) a white light fabric is stretched into the nozzle in front of the throttle, then the nozzle is placed. Then we gas and remove our tissue. Traces of oil will indicate an emerging turbine malfunction.
d) Clogged crankcase gas recirculation system.
Car engines are built in such a way that a small vacuum must be maintained inside the engine. This vacuum is created either by vacuum in the throttle area, or by special vacuum pumps(much less often). In any case, the exhausted crankcase gases are discharged into the intake manifold. But there are no pure gases in the crankcase, but there is oil mist. Because of what, these gases must be separated from them before being discharged into the intake manifold. This is exactly what the crankcase gas recirculation system does. When it fails, crankcase gases throw oil droplets into the intake, which can also cause the engine to smoke with a characteristic "oily" smoke.
e) Depreciation of the CPG (Cylinder-piston group).
A special case of point "d" is the wear of the cylinder-piston group (or the occurrence of rings, including compression ones). If oil scraper rings not stuck, but simply there is increased wear in the friction pairs.
This will result in an increased amount of exhaust gases entering the crankcase. Those. the amount of gas passing through the recirculation system will significantly exceed the calculated one. Of course, there will be a slip of oil drops into the intake and the result will be the same as in paragraph "d". Fault can be identified by opening the oil filler neck on working on Idling engine. With a working CPG and a crankcase gas recirculation system, air will be sucked into the neck (you can check with a piece of paper), or slightly out of it. If crankcase gases are knocked out of the neck with tangible force, it is worth thinking about serious repairs. It is also worth paying attention to the color of the gases coming out of the oil filler neck - ideally they are colorless. Check your assumptions about CPG wear you can check the compression. First, we measure the compression, then pour a little oil into the suspicious cylinder and re-measure. Details are described
e) Bad oil.
Do not discount bad oil. And here there are several options. Firstly, you could simply buy counterfeit goods. In this case, the properties of the oil alone .... are known. And how this oil will be separated in the crankcase gas recirculation system and how it will withstand high temperatures in the cylinder is not known:
Secondly - you could just overheat the oil. The fact is that engine oil, when exceeded allowable temperature loses its properties. Athletes know about this and install engine oil temperature sensors, additional oil coolers, etc. There is nothing like this in a normal car. And the car itself is not designed for extreme loads. And the pistons from the bottom are cooled just by engine oil! In normal life, the stock is enough. But imagine on a hot summer day you are going to rest: you have loaded your family, things (i.e., full load by weight), you have engine protection (interfering normal cooling oil in the crankcase) - where in Russia without it. Plus, there was a long climb on the way and ... voila, the oil is overheated. Should be changed without question.
g) The birthmark of many 16-valve engines are deep candle wells.
In these wells, there are several joints of mating parts. One for oil, the other for air. The result of a certain combination of circumstances will be the ingress of oil from the well to the engine suction:
Well, engine smoke final result. It is not difficult to check this - remove the candle tips and if they are in oil, then the gasket candle wells You are no longer able to perform your duties. If this is added to the lack of tightness of the intake manifold, the situation described above will turn out.
h) Original.
In addition to the described malfunctions that cause engine smoke, there are a number of rather exotic and even curious ones. For example: engine smoke (oil smoke) can be caused by a microcrack in the engine (quite difficult to determine) through which oil enters the intake or directly into the cylinder, or oil leaks and gets on the exhaust system elements.
Curious cases include cases when the owner of a car accidentally fills the tank with fuel intended for two-stroke engines(mixed with oil) and then in a panic looking for the cause of the engine smoking.
4) Engine smoking with clouds of steam.
Here the reason is quite unambiguous - water enters the cylinders. The place of its deployment is unambiguous - the engine cooling system. This means that it is quite simple to determine this by reducing the level of antifreeze. In addition, for a more accurate diagnosis, it is necessary to examine the candles. In a cylinder where water is present, the spark plugs will have scale deposits on the electrode that are fairly easy to spot. Try to clean such a candle with a needle file and you will be able to see a coating similar to the coating inside a kitchen kettle.
In this case, there are two main reasons - the head gasket has pierced, or a microcrack in the cylinder. Again, the reason for this is either an incorrect assembly or not quality spare parts, or OVERHEATING the engine (there are, of course, others, but these are the main ones). In any case, the repair is not delayed.
Sometimes the cause of fluid entering the cylinders can be corrosion of the engine from the inside (through!). Here is a picture I had the misfortune to see on one of my cars:
Not high-quality antifreeze literally ate the floor of the block from the inside. Corrosion products (simply rust) even filled expansion tank. Outcome - junk. Restoring such an engine is more expensive.
In a bad combination of circumstances, the coolant can get not only into the cylinders, but also into the oil! This is easy to determine by looking at the oil level dipstick.
You will not confuse the emulsion with anything. It's not worth the hassle here. In this case, before repair, I would advise flush the engine from the inside with diesel fuel. This will help save time and nerves during repairs, in addition to clean engine it will be easier to find the fault.
Good luck to you and all the best.
Key words: The engine smokes, why the engine smokes, the engine smokes with black smoke, the engine smokes with white smoke, the engine smokes with bluish smoke, water from the exhaust, the car smokes.
Edited snippet from the book "Japanese Car Repair."
Oil consumption is largely dependent on its viscosity (the thinner the oil, the more it flows through various seals) and quality.
Most car owners prefer to buy engine oil for their engine for reasons of "cheaper", but so that all the "labels", marking, packaging, company name - everything is in stock. With this approach, you can easily fall for a fake. Let's say you managed to buy a really branded and relatively cheap product, but the fact is that the vast majority of modern Japanese engines are highly accelerated units. There are four valves per cylinder, which means the engine is already boosted. Not to mention VVTi, Super Charge, Turbo systems, etc. A high degree forcing, in turn, means that all the "pieces of iron" inside the engine have a very high temperature. And for normal operation, all these "pieces of iron" require only elite and by no means the cheapest engine oil. Otherwise, overheating of the oil and its destruction follows. Open the filler neck on the valve cover of your engine. What do you see inside? That's right, black soot. Where is the soot from? Yes, oil. Cheap motor oil is destroyed by too much high temperature and settles on the walls. Oil burnout occurs and its level in the crankcase decreases. This, in turn, among other negative consequences, leads to a decrease in the oil level in the engine, which again does not have the best effect on its ability to cool in the oil pan. And that means that in the future there will be even more overheating of engine oil. The durability of an engine with such (cheap) engine oil, alas, is expected to be very low.
So the first disadvantage bad oil in the fact that it is destroyed by high temperature and actually ceases to be oil - that high quality product that the manufacturers recommend.
The second disadvantage of low-grade oils is that, when they break down, they pollute the engine with their decay products (soot). As a result, the piston rings barely toss and turn in their grooves due to this soot, but should “play”, continuously tracking the profile of the, alas, no longer ideal cylinder. The result of this phenomenon will be a defect known as the occurrence (coking) of the piston rings and the first, as follows from practice, the oil scraper rings will stop moving. As a result, no skimmed oil, which will burn. A car with a gasoline engine will smoke with a bluish smoke. Diesel - no. Any remaining oil in a diesel engine will burn without any smoke. The most curious thing is that if with this defect (the occurrence of oil rings) the compression is measured, the results will be excellent (oil compression). The oil not removed from the cylinder walls will seal the gaps in the compression rings and the pressure gauge will show the pressure even better than that of a new engine.
And the third thing that the use of low-grade oils will lead to is the destruction of all “rubber bands”. The rubber of all oil seals, seals, valve stem seals will lose its elasticity and turn into some kind of plastic. Naturally, after this, an oil leak will appear. When the car comes excessive spending engine oil, the following items are checked in turn.
1. Oil leak.
The engine starts, runs on the spot for about 30 minutes and is turned off. If there is at least one drop on a newspaper previously spread under the car, you need to fight the leak.
Quite often, during the operation of the car, the engine oil pan touches the bumps in the road. Usually the pan remains intact, there are not even noticeable dents that could lead to deformation of the oil receiver and subsequently create serious problems. But after such a touch, the pallet moves a little from its place and the sealant on which it was planted tears. After that, of course, there is a leak. The second reason for the leak is bad frontal seals, which change without any problems. Leak in rear seal crankshaft is a rather rare occurrence. Usually rear oil seal perekhazhivaet a couple of sets of front. The third reason is the little things (in terms of the amount of work to eliminate). It's a valve cover leak, a sensor leak. oil pressure(by the way, it’s very dangerous; there are cases when a minor leak of this sensor ended up dumping all the oil on the asphalt in a few minutes), a leak from under the distributor (this one, without noticeable consequences for oil consumption, can flow forever), etc.. Very rarely, but such cases occur, a leak is found from under the cylinder head. The head of the block in this case, as a rule, is warped due to overheating of the engine.
2. Crankcase ventilation.
Very often people complain that their turbine drives oil, referring to oil smudges on the turbine and air ducts. Although in fact the turbine (turbocharger) has nothing to do with it. When for some reason the seal (gland) leaks in this unit, it will be the seal operating in the worst conditions. That is, of the two seals, the seal on the turbine side, and not on the compressor side, will leak first, in which the temperature of all the glands is several hundred degrees lower, at least if the shaft has not burst in the turbocharger, i.e. if the turbocharger is destined to drive oil, then it will do it in the exhaust pipe. And after warming up, such a machine will smoke with a bluish smoke with a characteristic smell of unburned oil. And oil leaks at the joints of the air duct are simply due to the fact that the compressor is forced to compress air with oil. Where does oil come from? Yes, from the ventilation system. During engine operation, some amount of exhaust gases will inevitably enter the crankcase. There, these gases will mix with oil mist and become known as crankcase gases. And then through the valve cover (most often) they will be sucked into the intake manifold. Or, if the engine is turbocharged, into the duct before the turbocharger. True, all the oil in these gases should “beat off” in the oil separator and drain back into the engine crankcase, but sometimes this, for various reasons, does not happen. Then the oil does not separate from the gases and mixes with the sucked air through the ventilation tube. Further, compressed air(with oil vapors) slightly - slightly inflates (after all, the turbine creates pressure) rubber hoses, and those, being not quite tightly crimped at the joints, begin to “sweat”. To diagnose this, disconnect the crankcase ventilation and, using an additional rubber tube, bring it to plastic bottle, which is immediately engine compartment and fasten, the hole in the duct, of course, is closed with something. After that, we wash off all the oil leaks on the air ducts and ride 200 kilometers, if the air ducts become dry, and oil appears in the bottle at the bottom, then it’s not the turbine, but crankcase gases. And in this situation, you first need to check the ventilation system and, if it is in order, plan to repair the piston group or replace the engine, or, as an option, drive with a bottle, periodically pouring oil out of it into the engine. Now about what we do with the oil separation system, which is arranged in the valve cover (we are talking about diesel engines, since the ventilation system in gasoline engines, as a rule, does not cause problems). In general, all oil separators work in the same way. They carry out a sharp change in the direction of the flow of gases, as a result of which the oil settles on the walls. And then along these walls it flows into the "pan" of the oil separator and through a special hole into the engine (into the block head). This is where the design differences and problems begin. Most engines use following diagram . The oil flows down through the hole in the “sump” (in fact, it is a hole in the tin), and through the same hole there are more and more crankcase gases that carry oil. In theory, the “beaten off” oil should drain along the edge and not interfere with the gases. But if there are a lot of gases? The engine is old and worn out. Then the oil flowing down the walls (already “beaten off”) is picked up by gases and fed back into the oil separator. As a result, with this design, not “beaten” oil flies from the ventilation tube. What is the output? Make another hole in the tin? In general, it is possible, but who prevents the gases from going now not through a regular hole, but through a newly made hole? And in it again to pick up the "beaten off" oil? However, in this situation (with an increase in the through hole), the speed of crankcase gases will be less and they will pick up the beaten oil with less intensity. But in some designs there is a separate hole for "beaten off" oil, through which gases do not go. Since this hole is closed by a valve with a plastic ball. When oil accumulates in the oil separator pan, the ball floats and the oil flows out. This design is used in some Isuzu models and, as practice shows, is not very good. For our worn out cars. The problems are the same. No carbon deposits and too much crankcase gases. As a result, the engine again "drives" the oil through the ventilation. For some time now, Japanese designers have been using a water seal instead of a plastic ball. Then the oil flows not just through the hole in the oil separator pan, but through a tube that is lowered into the oil. To do this, a cup is fixed at the end of the tube, in which there is always oil. When this cup overflows from the dripping drops of "beaten" oil, the excess oil simply flows out into the head. Engines with this design for oil removal have practically no problems with excess engine oil in crankcase gases. A lot or not, can be defined as follows. We remove the ventilation tube and cover its end with one layer of ordinary thin fabric (of those used for sheets). After that, we start the preheated engine and light a cigarette (for those who smoke) or wait 3-4 minutes. If after this, the fabric is still not completely black, we consider that the oil separation system is working satisfactorily. If a piece of fabric turns black, and even more so if a drop forms on it, then ventilation definitely does not cope with its task. And we begin its repair by removing the valve cover and organizing a drain for broken oil. And so that crankcase gases do not go through this drain (hole), we make a water seal. For this purpose, cigar cases are excellent, the aluminum material of which makes it easy to manufacture any design.
3. Oil quality.
It's easy to check. Take the valve cover off and have a look. If everything under it is black, with thick deposits of fuel oil on all parts, then the oil consumption is, to a large extent, caused by its waste. Second option. If a week after changing the oil, it turned black again (we are NOT talking about diesel engines, where the blackening of engine oil still does not mean anything), then one of two things. Either the engine is terribly dirty and the new oil successfully dissolves this dirt in itself. Either the new oil is intensively destroyed and, naturally, decreases and at the same time is heavily contaminated by the products of its waste. By the way, this is a very common cause of engine failure. The owner of a forced Japanese engine, showing his commercialism, buys the cheapest engine oil. Yes, it's imported and works great. For example, in the engine of a Volga 21 car from a neighbor. But this engine does not heat up above 90 degrees in its entire life. While the temperature of Japanese engines almost constantly exceeds 100 degrees. This is where it starts to break down. branded oil. It just wasn't made for modern Japanese engines.
4. Engine smoke.
Let's talk about petrol engines first. The normal state of any gasoline engine- There is no smoke from the exhaust pipe. However, there is one exception here. The fact is that during the combustion of gasoline, as discussed in chemistry lessons at school, water is formed. Therefore, according to all the laws of physics and chemistry, steam must come out of the exhaust pipe. It goes if the temperature of the exhaust gases is not high. This happens in the morning, while the exhaust tract has not warmed up and in winter, when it is cold outside and the tract is simply not able to warm up. But if the engine exhaust system, warmed up - there will be no steam from the exhaust pipe, or rather it will not be visible. By the way, this is a note. If in the morning there is no steam from the exhaust pipe after starting the engine, then this indicates a malfunction of the engine. However, here it is necessary to make one clarification. Starting system carburetor engines, as a rule, turns off after 3-5 seconds. These are the seconds until the vacuum servomotor is forcibly opened air damper, the engine may emit black smoke and is not considered a fault. But if, after a few seconds after starting the engine, black smoke comes out of the exhaust pipe, but there is no steam, then we can assume that the engine is faulty and it has a too rich fuel mixture. If the engine is working, there should be steam. We will not consider black smoke from the engine. At normal cars(abnormal, these are those who, in order to increase power, have had the so-called "chip tuning" in order to successfully participate in sports competitions, well, and faulty machines) should not exist. And the appearance of black smoke seems to have nothing to do with oil consumption. And the gray (or blue) smoke is related. There are three main options for its appearance.
First option. The car with a warm engine stands still and works. There is no noticeable smoke from the exhaust pipe. But if, after about five minutes of running the engine at idle, you sharply press the gas pedal, a cloud of blue smoke will fly out of the exhaust pipe. If you immediately accelerate again - again a cloud. Accelerate a third time - the cloud of smoke will become smaller. Once again, even less. For the tenth time, when you sharply press the gas pedal, there will be almost no blue smoke. All this is a typical picture of such an unpleasant phenomenon as current valve stem seals. While the engine was idling, the oil through defective sealing gum(valve seals) slowly flowed down the valve stem to the back of the valve cap and remained there, in the form of a film. After all, the speed air flow at idle speed is not very large and therefore the oil had the opportunity to accumulate. Until the airflow speed increases. You pressed on the gas, the air flow increased and all the oil accumulated earlier was immediately sucked into the cylinders. New oil, of course, will run in again, but it, acting in small quantities, will not have a noticeable change in the color of the exhaust gases. And this oil has the ability to accumulate only at low speeds of intake air, i.e. at idle. Or when the engine is off liquid oil(engine is hot) what is left on the valve stem will not drain down completely. But there, on the stock, there is not much of it, and therefore there is also not very much smoke after launch. It should be noted that often the cause of engine oil getting into the intake (and exhaust) manifold is not only bad valve stem seals, but also worn valve guides. In this case, replacing the valve stem seals may not give a noticeable reduction in oil consumption (or give a short-term positive effect). In this case, it is necessary to remove the block head and replace the guide bushings. Also, not competent replacement of caps will not give a positive result. For example, if the master puts on caps with a hammer, he can very easily push the cap further than normal and thereby break it. We are not talking about fake caps, the rubber of which turns into “jelly” after a couple of months.
Second option. There seems to be no blue (gray, depending on the degree of engine warm-up and the degree of color blindness of the observer) smoke from the exhaust pipe. Neither when idling, nor when driving, when viewed through the rearview mirror. But remember how you are driving uphill, where almost all drivers are pressing on the gas pedal. There is no smoke at all behind one car in front, and blue smoke curls from the exhaust pipe of another. Moreover, the driver sitting in that car in the rear-view mirror does not see this smoke: there is too little of it. But you, who are following, can see this smoke. And he says that the front car has problems with the piston group, as a result of which it also has an increased consumption of engine oil. This is indicated by the gray (blue) smoke. These problems with the piston group may be as follows.
1. Wear of piston rings. The reason - usually due to savings on air filters and engine oil. "Cure" by replacement.
2. Wear of the groove for the piston rings. The groove has become too wide and because of this, a "pumping effect" occurs when the engine is running. "Treated" by replacing the pistons. But, according to "poverty", options are possible. See point 6.
3. Occurrence of oil rings. "Treated" by mechanical cleaning during disassembly.
4. Wrong position of compression rings. When the piston moves, the ring is pressed against the wall of its groove and constantly “plays”, tracking the profile of the cylinder. If there is soot on this wall, then the ring, clinging to it and at the same time barely moving in its groove, will not “play”. After all, the thickness of the soot is not uniform and, therefore, the ring will warp. Well, it’s not right to seal the piston-cylinder gap. "Treated" mechanical removal soot.
5. Cylinder wear. The wear process is always uneven and begins with the first start of the engine. But the piston rings, "playing" in their grooves, when the piston moves, constantly monitor the profile of the cylinder and everything is more or less decent. But, in the end, the wear of the cylinder profile becomes so great that the rings are no longer able to do their job (seal the piston-cylinder gap). If carbon deposits or too thick engine oil interfere with the operation of the rings, this occurs with less cylinder wear. Engine compression is reduced. "Treatment" by boring the cylinder to the repair size or sleeve. But there is serious problem. Both of these operations (both boring and sleeve) involve the use of abrasive tools, for example, for honing. The use of an abrasive tool, in turn, leads to the fact that part of the abrasive particles is embedded in the material being processed. And it is very difficult to remove these particles. In large enterprises, ultrasonic washing is used for this, but what should auto repair shops do? Well, they wash as best they can. Accordingly, the engine resource after such a repair is unlikely to exceed 100 thousand km. True, owners of cars with engines that have sleeves “for life” (from birth), such as Mitsubishi 4D-56, Mazda RF, etc., have a witty way out. The worn sleeve is pressed out, turned over and pressed in again. In practice (not from a good life, of course) it has been verified that even if the cylinder (sleeve) is worn out, a “step” of 1 mm has formed, the sleeve can still be used “upside down”. With such wear, even in order to remove the pistons, it is necessary to “smooth out” the step with a drill. Otherwise, the compression rings, resting against the shoulder, will not allow the piston to be knocked out. As a result, a pit forms on the surface of the sleeve, but, nevertheless, just below the pit, traces of honing are already visible, a symbol of the absence of wear. Therefore, such an engine, with inverted sleeves, works quite well - there is no oil consumption. We know the old Delica, which has already covered 130 thousand km with inverted sleeves without noticeable signs of wear of the piston group.
6. Wear and destruction of pistons. "Cure" by replacement. Although you can melt. The result will be “not very”, it strongly depends on the qualification of the welder, but still. At one time when the spare parts on Japanese engines there were almost none, the destroyed bridges between the grooves for the piston rings were welded. But after that, it was necessary to carry out heat treatment and machining of the entire piston, so that its dimensions corresponded to decency. The jumpers burst when the grooves are very worn and when the rings constantly hit their walls, which leads to a significant decrease in compression and increased consumption engine oil. This breakdown is more likely if too early ignition and when using low octane fuel. Jumpers almost do not burst on old Nissan engines (they are just very wide) and on 2-liter in-line "sixes" of all companies. There, the piston diameter is small and the detonation wave, which hits the rings (and they already break the jumpers), does not have time to accelerate much. Melted firing belts on pistons (mainly for diesel engines due to poor fuel mixture) can also be welded, but in this case there are usually teases on the skirts. Therefore, it is more reliable to find other pistons. Well, or start making new ones. On this subject in the book by A.E. Khruleva "Repair of engines foreign cars” publishing house “Behind the Rulem” argues in some detail and convincingly.
So, if blue (or bluish) smoke comes out of the exhaust pipe, and how more speed car, the more this smoke, you need to undergo diagnostics and you may have to disassemble the engine.
Third option. There is a lot of smoke from the exhaust pipe or there are patterns in under which operating modes it is more and under which it is less. We will not consider cases where a large amount of smoke from the exhaust pipe is associated with the flow of coolant into the cylinders (the smoke is whiter and has a sweetish smell) here we will not consider, since this is related to the cooling system and is a separate topic. A large amount of blue (gray) smoke from the exhaust pipe can be if the turbine is broken (for turbocharged engines), the crankcase ventilation system is faulty, the intake manifold geometry change system and late fuel injection (for diesel engines) are faulty. Let's consider these cases in more detail.
The turbine broke. If an oil seal (oil seal) is destroyed in a turbocharger, then the oil that is supplied to this turbocharger under pressure to lubricate the shaft will begin to flow into the exhaust pipe and, naturally, burn there. But only after the exhaust pipe heats up. On this basis, the machine begins to smoke intensively after warming up, and it is assumed that the turbine seal is faulty. Usually in these cases, the flow of oil into the exhaust pipe is so abundant that it oozes along the joints (flanges) of the exhaust tract and even drips from the muffler.
Faulty ventilation system. When using low-quality grades of engine oil in highly accelerated engines, which are the majority of Japanese engines, this low-grade oil is rapidly destroyed. The internal surfaces of the engine, in particular the valve cover, are covered with oil decomposition products, that is, soot. When there is a lot of this soot, it clogs the oil separator and after that the crankcase gases are no longer cleaned of oil. We had such a case with a six-cylinder V-engine. The car could smoke blue smoke with a smell burnt oil, and could not smoke. And there was no regularity or pattern. It stands, idling and there is almost no smoke from the exhaust pipe. It takes several minutes (even tens of minutes) and suddenly smoke comes out of the chimney. Two - three minutes, and again everything is decent. There is no smoke. Removed the intake manifold, and it is full of oil. By oil drips on the inner walls, we traced where the oil came from - from the ventilation hole. We remove the valve cover, and there everything is in black oil "stalactites". After that, I wash the valve cover from the outside and drill (it is riveted) the fastening of the oil separator cover. We remove the cover - everything inside is clogged with asphalt. Including an oil drain hole. Next, we go to the hardware store and buy a few dozen screws, the shortest ones. After that, in place of the rivets, we drill holes for these screws and, as expected, fasten the cover onto the sealant. The aluminum material of the valve cover allows the screw to be screwed in like a self-tapping screw, i.e. without thread cutting. It is enough just to make a hole for the self-tapping screw a few "tens" less.
If the engine had been simpler with this malfunction (completely non-working oil separator), then it would not have been possible to easily calculate the malfunction. And the “abstruse” V-shaped intake manifold allowed the oil to accumulate in various cavities and then flow into the cylinders in one gulp. After such "volley" discharges of engine oil, there was a sharp increase in smoke from the exhaust pipe. If I came with such a problem diesel engine then there would be no smoke. After all, engine oil, once in the cylinders, burns out, as you know, no worse diesel fuel. And only by oil leaks at the junctions of the intake manifold and air ducts one could suspect that not everything is in order with the ventilation system. If all the joints are sealed ... But this is rarely the case, especially if the engine is equipped with a turbocharger. The fact is that in the presence of a turbocharger, the pressure in the intake manifold changes periodically. All rubber spacers, when the boost is “turned on”, are slightly inflated and “fidget”, which is why the seals are broken. As long as the "gum" is "fresh", there are no leaks. But as soon as they “zadubet” a little, oil streaks appear.
Changing the geometry of the intake manifold.
For some engines, the drive of the dampers that block the air channels in the intake manifold is made inside the engine. For example, in the "1S" series engines, this drive is located under valve cover. Moreover, even the vacuum servomotor communicates with the space under the valve cover. And there, of course, oil mist. If the diaphragm of the servomotor breaks, then every time it is triggered, the oil from the engine, together with crankcase gases, will vacuum tubes control enter the intake manifold. The engine will emit blue smoke. If the damper shafts "break" in their guides, engine oil will also flow into the intake manifold. And the engine will again smoke and “eat” oil. When we encounter such a problem, we turn off the servo motor and disconnect the actuating damper actuators. After that, the dampers become “downwind”, there is no geometry control system, and the engine does not “eat” oil. The damper shafts stop rotating back and forth and the flow of oil along them, and hence the flow, is reduced. The decrease in power after such a “modernization” is not even noticed by normal drivers. Moreover, this reduction occurs in a narrow range of engine speeds.
Thanks to dear S from forum.auto.vl.ru
My viburnum smoked blue on a cold one. I open the whole topic.
So, I will tell you about the reasons why the car smokes. But first I’ll tell you what happened in my case, and later on in general about general possible problems, the Internet is full of standard articles!
My car, viburnum 1.4 16 valve, smoked blue smoke, and when it just started, you sharply give gas. After a while (a couple of minutes) the smoke passed. And sometimes it smoked at a traffic light when it gasped sharply.
The problem of blue smoke is when oil gets into the fuel and burns - and it turns out blue smoke.
In my case, the situation was quite terrible ... They made the head of the engine, the oil, removable caps changed, exhaust valves, piston and rings. All this turned out to be quite expensive ... Who cares about the prices: the rings from the piston to the viburnum 1.4 are special, not killed and seem to be German and it is very difficult to get them ... I got them for 7000r. Head repair 5000r. Well, plus the little things ... It cost me so, because. my family's car service. After that, my machine stopped smoking completely and now it flies, well, or almost ... I haven’t done everything on it yet ...
Now for the possible reasons:
Why does the car smoke blue smoke (color).
The main reason for the appearance of blue or gray smoke is the combustion of oil, which means that oil enters the engine cylinders. So, if there is blue smoke, it means that your machine decently eats oil! Check his level! Oil can enter through the gaps of the piston, rings, between the valve stem and guide bushings.
The main reason for the appearance of such a haze is the wear of the piston, rings and cylinders. Often in this case there is a loss of compression! Here you have to be very careful, because. there are times when there is no loss of compression and it is difficult to determine the cause of blue smoke.
If it smokes only on a cold one, it means that the wear is not great and the oil does not get enough ... Here you can wait a little with the replacement of the piston and climb into the head of the car. The reason may be too thin oil! Or there was not much wear on the engine. In order to prevent oil from entering the combustion chamber in such cases, try replacing the oil with a thick one. Also try using additives that keep oil from entering the combustion chamber at small gaps.
If the wear is small, blue smoke appears on a cold start and disappears after a while.
If the wear is excessive, blue smoke may only appear on a warm engine or increase along with an increase in warm-up.
Blue smoke and oil consumption very often also appear when one of the cylinders is turned off due to an ignition malfunction (for example, if the ignition coil burned out) or if the valves are not tight. Also, candles will have black soot and possibly with growths!
