Tar deposits on engine valves. Dirt and deposits in the combustion chamber of the internal combustion engine of a car

» Carbon deposits in the engine - cleaning carbon deposits and oil deposits

Carbon deposits in the engine as well as fatty deposits of oil is an inevitable process. This applies to gasoline and diesel power units. The formation of soot and coke is associated with the use of low-quality fuel and takes place under conditions of high t 0 combustion of the fuel and air mixture in a closed chamber. If we characterize soot in a few words, we can say that this is a layer of unburned deposits that settles on the walls of the engine combustion chamber.

Long term operation vehicle leads to the progress of coking and engine deposits. At some point, carbon formation can cause malfunctions and " technical illnesses» diesel installations and gasoline internal combustion engines.

In the article you will learn about the signs of internal combustion engine pollution and the consequences. Questions are raised effective fight with this phenomenon, signs of soot in the engine and possible consequences coking power plants. Traditionally, at the end of the article, we summarize.

Signs of engine contamination

Before we figure out how to clean the engine from carbon deposits, let's decide what are the main signs unstable work power plant and the first symptoms of the disease.

note !

The process of carbon formation accelerates engine oil, which, with poor-quality tightness of parts power unit enters the combustion chamber. The oil burns along with the fuel, accelerating the deposit process.

Malfunctions that may occur as a result of soot:

1. Often, these are problems associated with starting the power plant "cold".
2. When the "engine" is started, it smokes and works unstably.
3. There are problems of gas exhaust with an admixture of burning.
4. Oil consumption often increases.
5. Loss of engine power.
6. There is an increase in fuel consumption by 10-15%.
7. Detonation occurs, the engine quickly heats up and overheats, working at high speeds.

Having familiarized yourself with the signs of contamination in the motor, you need to dwell on the consequences of soot.

What can happen if there is carbon deposits in the engine

It is important that deposits adversely affect the overall stable work, which ultimately leads to excessive consumption of fuel and technical fluids. And also, it increases the risk of engine breakdown: as a result, the likelihood of a serious engine repair increases significantly. Let's move on to concrete examples negative consequences. It could be:

• soot on valves that open only partially;
• deposited soot on piston rings leads to their occurrence;
• from the process of smoldering soot particles, uncontrolled ignition can occur combustible mixture.

The situations described above can eventually lead to a critical situation.

Due to severe coking, the valve cannot close completely. Which leads to the occurrence of rings. This reduces the compression in the engine. Naturally, it does not start well, failures occur in its work.

As a result, the valves burn out, which eventually leads to the need repair work which are not cheap. Unauthorized ignition of the fuel-air mixture provokes potash ignition due to smoldering deposits.

Diesel and/or petrol plant overheats quickly. This, in turn, leads to premature wear engine parts and adversely affects fuel and exhaust systems.

You can extend the life of engine parts by washing slag and deposits. If the first signs of this phenomenon appear, you need to clean the clogged engine from soot. Read about it below.

About the main ways to get rid of coke and deposits

In practice, you can get rid of the pollution problem:

1. By completely disassembling the engine and removing carbon deposits mechanically, using abrasive tools.
2. Clean the motor with special means flushing.

However, flushing may not be as effective as desired and only partially solve the problem. And dismantling the power plant is troublesome and responsible. In fairness, it must be said that disassembling the motor allows you to completely eliminate soot.

But, there are a number of ways to clean deposits from internal combustion engines without resorting to cardinal methods, one of which can be considered a complete disassembly of the internal combustion engine. We are talking about removing carbon deposits without disassembling the engine .

The procedure for cleaning the motor from carbon deposits

First of all, you need to unscrew the candles:

On cars running on gasoline, these are spark plugs.

1. Through candle wells in the cylinders you need to fill in the "decoking" - this is a special liquid.
2. A pause is needed for the special liquid to do its job: soften the deposits. This will take approximately 2-3 hours.
3. Next, unscrew the candles, start the engine. During its operation, deposits will burn out and be removed from the engine cylinders.
4. The procedure involves at the final stage necessary replacement oils in the power plant and oil filter.

There are other ways to remove carbon deposits that have been proven in practice. We are talking about a multicomponent mixture based on acetone. To prepare the mixture you will need:

1. 2 parts acetone, which can be replaced with a solvent.
2. One part kerosene.
3. One part engine oil.

And further

Flushing the engine with diesel fuel before the next shift technical fluid- this is an old and effective way to get rid of scale and coke, and also helps to rejuvenate the entire oil system. It is simple, affordable and safe way get rid of deposits and scale.

How else can you flush the engine from the inside. Can be injected with a syringe into a rubber tube passing between vacuum regulator and carburetor, insert the needle of the injection system. Lower one end into a container with water, which, due to vacuum, enters the carburetor and enters with air-fuel mixture into the engine cylinders. The procedure is recommended to be carried out on a working power plant. The outgoing steam softens the deposits and helps them to come out. The process takes no more than 10 minutes.

A fuel additive can be used to remove deposits. This method solves the problem, the effect really exists. The most popular automotive chemicals are products French manufacturers. Fuel additives have a high detergency and cope with dirt. This method works for diesel plants and petrol units.

Speaking about car maintenance, when changing the filter, it is important to use the oils recommended by the manufacturer. Pay attention to the synthetic all-weather production in France. It reduces the friction of engine parts and allows you to easily start the engine at t 0 to -35 0 С.

A product made in France, Total oil ensures easy operation of the engine, protects it from dirt. Oil total can be mixed with other standard engine oils.

Summing up, we can say

Knowledge of the problems will help to find effective way elimination of coke and scale. But the main thing is the care of the motor, timely replacement oils and components during maintenance.

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Changing the properties of the oil in a running engine

The main changes in properties in a running engine occur for the following reasons:

1. high temperature and oxidizing effects;
2. mechanochemical transformations of oil components;
3. permanent accumulation:

• conversion products of oil and its components;
• fuel combustion products;
• water;
• wear products
• contaminants in the form of dust, sand and dirt.

Oxidation

In a running engine, hot oil constantly circulates and comes into contact with air, products of complete and incomplete combustion of fuel. Air oxygen accelerates oil oxidation. This process is faster in oils prone to foaming. metal surfaces parts act as catalysts for the oil oxidation process. The oil heats up in contact with heated parts (primarily cylinders, pistons and valves), which greatly speeds up the process of oil oxidation. The result can be solid oxidation products (deposits).

The nature of the oil change in a running engine is influenced not only by the chemical transformations of the oil molecules, but also by the products of complete and incomplete combustion of the fuel, both in the cylinder itself and breaking through into the crankcase.

Effect of temperature on engine oil oxidation.

There are two types temperature regime engine:

• operation of a fully warmed-up engine (main mode).
• operation of an unheated engine (frequent car stops).

In the first case, there is high temperature mode of changing the properties of the oil in the engine, in the second - low temperature. There are many intermediate working conditions. When determining the level of oil quality, motor tests carried out in both high-temperature and low-temperature regimes.

Oxidation products and changes in engine oil characteristics.

acids(acides). The most significant products of oil oxidation are acids. They cause corrosion of metals, and alkaline additives are consumed to neutralize the resulting acids, as a result of which the dispersant and detergent properties and reduced oil life. An increase in the total acid number, TAN (total acid number) is the main indicator of the formation of acids.

Carbon deposits in the engine(carbon deposits). A variety of carbon deposits form on the hot surfaces of engine parts, the composition and structure of which depend on the temperature of the metal and oil surfaces. There are three types of deposits:

• soot,

• sludge.

It must be emphasized that the formation and accumulation of deposits on the surface of engine parts is the result of not only insufficient oxidative and thermal stability of the oil, but also its insufficient detergency. Therefore, engine wear and reduced oil life is a complex indicator of oil quality.

Nagar(varnish, carbon deposits) are products of thermal destruction and polymerization (cracking and polymerization) of oil and fuel residues. It is formed on strongly heated surfaces (450° - 950°C). Nagar has a characteristic black color, although it can sometimes be white, brown or other colors. The thickness of the deposit layer periodically changes - when there are a lot of deposits, heat removal worsens, the temperature of the upper layer of deposits rises and they burn out. Less deposits form in a warm engine running under load. According to the structure, deposits are monolithic, dense or loose.

Nagar has a negative effect on the operation and condition of the engine. Deposits in the piston grooves around the rings prevent their movement and pressing against the cylinder walls (jamming, sticking, ring sticking). increases the breakthrough of gases into the crankcase and oil consumption Pressing the rings with deposits to the cylinder walls leads to excessive wear of the cylinders (excessive wear).

Cylinder wall polishing(bore polishing) - deposits on the top of the pistons (piston top land) polish the inner walls of the cylinders. Polishing prevents the oil film from retaining and retaining on the walls and significantly accelerates the wear rate.

varnish(lacquer). A thin layer of brown to black, hard or sticky carbonaceous substance that forms on moderately heated surfaces due to the polymerization of a thin layer of oil in the presence of oxygen. The skirt and the inner surface of the piston, connecting rods and piston pins, valve stems and lower parts of cylinders. The varnish significantly impairs heat removal (especially of the piston), reduces the strength and persistence of the oil film on the cylinder walls.

Deposits in the combustion chamber(combustion chamber deposits) are formed from particles of carbon (coke), as a result of incomplete combustion of fuel and metal salts included in the composition of additives as a result of thermal decomposition of oil residues entering the chamber. These deposits heat up and cause premature ignition of the working mixture (before a spark appears). This kind of ignition is called preignition or preignition. This creates additional stresses in the engine (detonation), which leads to accelerated wear bearings and crankshaft. In addition, individual parts of the engine overheat, power decreases, and fuel consumption increases.

Clogged spark plugs(spark plug fouling). Deposits accumulated around the spark plug electrode close the spark gap, the spark becomes weak, and the ignition becomes irregular. As a result, engine power is reduced and fuel consumption is increased.

Resin, sludge, resinous deposits (sludge) (resins, sludge, sludge deposits) in the engine, sludge is formed as a result of:

• oxidation and other transformations of oil and its components;

• accumulation in the oil of fuel or decomposition products and incomplete combustion;

• water.

Resinous substances are formed in oil as a result of its oxidative transformations (crosslinking of oxidized molecules) and polymerization of oxidation products and incomplete combustion of fuel. The formation of resins increases when the engine is not warm enough. Products of incomplete combustion of fuel break into the engine crankcase during prolonged operation on Idling or stop-start. At high temperatures and intensive engine operation, the fuel burns more completely. To reduce tar formation and engine oils, dispersant additives are introduced that prevent coagulation and precipitation of resins. Resins, carbon particles, water vapor, heavy fuel fractions, acids and other compounds condense, coagulate into larger particles and form sludge in the oil, the so-called. black sludge.

Sludge(sludge) is a suspension and emulsion in oil of insoluble solids and resinous substances from brown to black. Composition of crankcase sludge:

• oil 50-70%

• water 5-15%

• products of oil oxidation and incomplete combustion of fuel, solid particles - the rest.

Depending on the temperature of the engine and oil, the processes of sludge formation are somewhat different. Distinguish between low temperature and high temperature

Low temperature sludge(low temperature sludge). It is formed when breakthrough gases containing fuel and water residues interact with oil in the crankcase. In a cold engine, water and fuel evaporate more slowly, which contributes to the formation of an emulsion, which subsequently turns into sludge. The formation of sludge in the crankcase (sludge in the sump) is the cause of:

• increase in viscosity (thickening) of the oil (viscosity increase);

• clogging of channels of the lubrication system (blocking of oil ways);

• oil supply disturbance (oil starvation).

The formation of sludge in the rocker box is the cause of insufficient ventilation of this box (foul air venting). The resulting sludge is soft, friable, but when heated (during a long trip) becomes hard and brittle.

high temperature sludge(high temperature sludge). It is formed as a result of the combination of oxidized oil molecules under the influence of high temperature. An increase in the molecular weight of the oil leads to an increase in viscosity.

IN diesel engine sludge formation and an increase in oil viscosity are caused by the accumulation of soot. Soot formation is facilitated by engine overload and an increase in the fat content of the working mixture.

additive consumption. Consumption, the operation of additives is the determining process of reducing the oil resource. The most important engine oil additives - detergents, dispersants and neutralizers - are used to neutralize acidic compounds, are retained in filters (together with oxidation products) and decompose when high temperatures. The consumption of additives can be indirectly judged by a decrease in the total base number TBN. The acidity of the oil increases due to the formation of acid oxidation products of the oil itself and sulfur-containing products of fuel combustion. They react with additives, the alkalinity of the oil gradually decreases, which leads to a deterioration in the detergent and dispersant properties of the oil.

The effect of increasing power and forcing the engine. The antioxidant and detergent properties of the oil are especially important when boosting engines. Gasoline engines are boosted by increasing the compression ratio and crankshaft speed, and diesel engines by increasing effective pressure (mainly with turbocharging) and crankshaft speed. With an increase in the crankshaft speed by 100 rpm or with an increase in effective pressure by 0.03 MPa, the piston temperature increases by 3°C. When forcing engines, their mass is usually reduced, which leads to an increase in mechanical and thermal loads on parts.

Motor oils "Automobile lubricants And special liquids» NPICC, Saint Petersburg. Baltenas, Safonov, Ushakov, Shergalis.

While the engine is running internal combustion it constantly happens, which leads to their abrasion and engine wear. Whatever the oil is and how often you do not change it, there will be wear. To reduce friction in internal combustion engines, special measures are used - the supply of lubricant to rubbing surfaces or its static presence in friction units (usually this is grease in rolling bearings). The lubricating substance in the engine is engine oil, which in most cases is of petroleum origin. Oil is supplied to the lubrication system under pressure, which develops a gear (or other type of pump) pump. Oil flows through the channels to all rubbing surfaces, reducing the friction force and cooling the parts. The channels in the lubrication system have a certain cross-section and capacity, and the higher this capacity, the better the lubrication and the longer the life of the engine. But the channels cannot be made excessively large, as this will lead to a decrease in strength, therefore the channels have strict geometric parameters.

If the owner of the car used low-quality engine oil or violated the intervals for replacing it, then a harmful phenomenon manifests itself brighter in the engine - deposits of dirt and soot. Various kinds of deposits narrow the oil channels and reduce the performance of the lubrication system as a whole, lead to unbalance of rotating parts and oil starvation all rubbing surfaces, especially those that are at a considerable distance from oil pump(distant main journals and connecting rod journals, timing) and to local overheating of parts and assemblies.

Deposits in the piston grooves around the rings prevent their movement and pressing against the cylinder walls (jamming, sticking, ring sticking). As a result of jamming and difficulty in the movement of the rings, they do not press against the walls and do not provide compression in the cylinders, the engine power drops, gas breakthrough into the crankcase and oil consumption increase. Pressing the rings with deposits against the cylinder walls leads to excessive wear of the cylinders.

Cylinder wall polishing - deposits on the top of the pistons polish the inner walls of the cylinders. Polishing prevents the oil film from retaining and retaining on the walls and significantly accelerates the wear rate.

Deposits in the combustion chamber are formed from carbon particles, as a result of incomplete combustion of fuel and metal salts included in the composition of additives as a result of thermal decomposition of oil residues entering the chamber. These deposits heat up and cause premature ignition of the working mixture (before a spark appears). Such ignition is called pre-ignition or pre-ignition. This creates additional stresses in the engine (detonation), which leads to accelerated wear of the bearings and the crankshaft. In addition, individual parts of the engine overheat, power decreases, and fuel consumption increases.

Recall that on a serviceable car, the oil suddenly turned into a thick black slurry, after which the motors were sent for a “capital” or replacement - untimely and extremely expensive. without even asking our permission. Well, that's okay...

Summary previous article - a wave of sudden engine failures has swept through branded car services (and not only), associated with incomprehensible and unpredictable behavior of engine oil. Without any warning, the oil suddenly turned into a black oil, began to burn out very quickly. The result - overhaul or death of motors.

The epidemic hit cars regardless of their brands and manufacturers. Cases of the disease were registered in Moscow, and in St. Petersburg, and in Magnitogorsk, and in Murmansk - that is, almost throughout the country. And it was also noticed that the “sick” were mainly cars serviced at serious car services, in which barrel branded oil was poured. The situation was aggravated by the fact that these cases were irregular, met infrequently, but with enviable regularity. And, as any diagnostician knows, it is the “floating” defect that is the most difficult to catch.

The cause of this illness was incomprehensible, there were only hypotheses, but you can’t build a lawsuit in court on them (and most often it was the case that reached the court in proceedings). And then we promised to try to deal with the situation and acquaint our readers with the results.

Six months of work of our testing laboratory was not in vain. We managed to simulate a number of situations in the laboratory and, finally, get clear manifestations of this “deadly disease”. The symptoms that we will catch are a sharp increase in viscosity, a drop in alkaline and an increase in acid number, the deposition of thick tar-like deposits on the engine walls that prevent oil from pumping through the channels of the lubrication system.

IS THE OIL IN THE CANISTER SEPARATED? IS THERE RESIDUE? TO THE WASTE!

FALSE TRAIL

Let's start with the typical "excuses" of dealer service stations, on the basis of which they are trying to fight off warranty repair. The inquisitive mind of warranty specialists usually wanders in three directions - the use of low-quality fuel; antifreeze or water getting into the oil; lack of control over the oil level in the engine during operation.

Let's immediately remove the third option - it is obvious that even with a very small amount of oil in the sump, it should not change its properties in the way that we see in cases of advanced "disease". When using a “healthy” oil, the motor will react to a small amount of it by catching fire control lamps on dashboard and sound alarm. First - with rolls and sharp accelerations and decelerations, when the receiving fungus is exposed. Any normal driver will respond to this immediately. And after topping up the oil, you will not feel any negative consequences in the future.

The most common alleged "reason" on the basis of which they try to void the warranty is the use of substandard fuel. Substandard in the understanding of service station mechanics is either a low octane number, or high content sulfur in the fuel, or the presence of a large amount of resins in it. Let's say right away that, apart from sulfur, everything else is current Technical Regulations, which regulates the quality of fuel, is not subject to control, therefore, it is not subject to jurisdiction. But, since there are such attempts at excuses, we will check.

FUEL - JUSTIFY!

Several bench engines, initially completely serviceable, were doomed to the slaughter. It’s a pity for them, but these are just pieces of iron, and living people suffer from the problem. Therefore - let these motors serve for the benefit of people.

Especially for the experiment, not without difficulty, they got 100 liters of fuel, more like a bodyagi. Instead of the declared 92 octane number, only 89.5 were measured, the sulfur content went off scale over 800 ppm, the tar was more than 3.5 mg / dm3. The manufacturer is unknown, but in terms of quality it is something from some kind of "samovar" - an amateur mini-refinery that distills gas condensate into supposedly fuel. Worse than ever! You have to dislike your car very much to feed it with such good things.

We fed the engine all the bodyag we got. And, in order to completely aggravate the situation and provide the oil with the maximum possible contact with disgusting fuel, they broke off the side electrode on one of the candles. Now the fuel entering idle cylinder, in large quantities will fly into the crankcase.

The motor self-diagnostic system was indignant, the check-engin burned brightly and incessantly all the time of torture. The motor shook and vibrated, but... survived! His autopsy revealed no problems - everything was clean and no black deposits were observed anywhere. The oil pressure, of course, dropped a little - the dilution of the oil by the fuel affected. At the same time, as soon as the damaged candle was replaced with a normal one, literally half an hour later, the arrow of the oil pressure indicator returned to its previous position. It is understandable, gasoline is a volatile liquid, and at operating temperatures the oil into which it has entered will not live there for a long time.

Measurements of the physico-chemical parameters of the oil did not reveal anything unexpected! The viscosity of the oil dropped a little - after all, some fuel fractions of the so-called gasoline remained in it. Base number slightly decreased - from 7.8 to 7.4 mg KOH/g. The acid number increased by 0.3 mg KOH/g. The flash point dropped noticeably - from 224°C to 203°C. This clearly indicates that there was gasoline in the oil! But he couldn't kill him...

Moreover, in a real situation, its diagnostic system will be indignant at the poor-quality feeding of the motor in the first place. And this indignation is sure to leave an indelible mark on the computer logs. But in almost all cases when the warranty services refused to repair, motivating their decision to use low-quality fuel, the diagnostic system did not confirm anything of the kind.

Verdict: Gasoline not guilty!

SUSPECTED WATER

Water always gets into the oil in some quantities! It condenses from the moist air entering the cylinders and, together with crankcase gases, mixes with the oil. Coolant can only get into the oil if there is a leak in the cooling system - and only when the engine is stopped. During its operation, the oil pressure is higher than the pressure in the cooling system, and therefore the path for antifreeze to the oil is closed.

Well, let's try to simulate this situation. 3 liters of fresh oil were poured into the long-suffering engine, and then a whole liter of water was thrown into it! And what? Never mind! Of course, an emulsion formed in the sump, the oil pressure dropped noticeably. But the motor worked, nothing critical was heard or seen. And then - gradually the oil pressure began to grow and soon returned to First level. What happened? The water simply evaporated, the oil returned to its original state. The autopsy of the motor showed no problems - everything was clean again. Changes in the physical and chemical parameters of the oil after the ingress and subsequent evaporation of water turned out to be within the measurement error! And this is the reason for the withdrawal from the guarantee - to refuse for insolvency!

After that, they dealt with a similar situation by replacing the water with antifreeze. The result is the same, the engine survived. But the viscosity of the oil has grown - it is understandable, the water has evaporated, and the ethylene glycol remains in the oil. The alkaline number decreased slightly, the acid number increased. Yes, of course, if you drive an engine with a broken cylinder head gasket for a very long time, constantly adding antifreeze to the tank and not trying to deal with the situation, then in the end, you can probably achieve the death of the oil, and with it the death of the engine! But this is just an extreme case of a disregard for the engine. Yes, and here there will already be a situation - not “ethylene glycol in oil”, but “oil in ethylene glycol”.

Conclusion - such a reason can only be considered when it was preceded by a long and constant loss of coolant in the engine. And with a complete lack of control of the condition of the oil at the same time. This is also not our case.

Verdict: It's not the coolant's fault!

GOT!!!

We checked two more versions. And, looking ahead, let's say - THEY WORKED!

The first one was suggested by oil specialists, with whom we constantly communicate. According to them, the picture that we are seeing, that is, sharp rise viscosity of the oil, may be due to the unexpected polymerization of some components of the additive package. The reason for this disgrace is the volumetric overheating of engine oil. And they remembered that at their seminars, some manufacturers of oils and cars, since recently, began to give a clear recommendation - if suddenly the oil was overheated, then you urgently need to run to the nearest service center and change it!

We tried to overheat the oil on a bench motor. It was not difficult for us to do this - we had to turn off the external engine airflow and select the appropriate operating mode. Unlike most cars, our sump oil temperature is constantly displayed on the control panel. Indeed, it rose by 20...25 degrees. This torture continued for many hours. Two oils worked fine, withstanding such a mockery. But the third behaved strangely - it began to noticeably thicken. And then, in the drain tank, where they left its remains for a couple of days, traces of oil separation were found. It drew the same “tar” that we observed on the walls of motors killed by oil. Both on the inner surface of the cylinder block and on the side surfaces of the pistons, there was much more contamination than usual.

So, we opened one option for the death of oil. But they didn’t experience much joy from this - after all, it’s not clear how you can track the real temperature of the oil in the sump in a living car? Indeed, in new cars, even the coolant temperature gauge was removed! It turns out that this information is not even redundant at all!

Let's go further... We remembered how it all started. It all started with a letter from our reader, who, having bought a canister of oil for topping up, was very well-known company, suddenly discovered in it ... an incomprehensible sediment! And from the answer technical specialist the Russian representative office of this company, which, in response to our request for an explanation of the situation, literally uttered the following: “I hereby inform you that in motor and transmission oils a small amount of sediment is allowed. It can be caused by the association of fine catalyst particles that are smaller than the pores of the factory filter element. These sediments... can be up to black in color. They are rare and, as a rule, only in those batches of oil that were made immediately after reloading the fresh catalyst in the apparatus. On performance characteristics commercial oil does not have any effect and, subsequently, in the process of work, they again pass into a finely dispersed state.

At one time, our oilers were shocked by this answer! That is, one of the world's main oil producers honestly admits the possibility of a gross violation of oil production technology!

And we compared what is written and what we saw with our own eyes. After all, the premature death of oil is very similar to the picture that we could see due to a sharp acceleration in the rate of oil oxidation. It is this process that is accompanied by an increase in its viscosity and acid number, a drop in base number. And what can contribute to the uncontrolled acceleration of the chemical reaction, which, in fact, is the oxidation of oil? Precisely the presence of a catalyst!

Yes, of course, when storing such a “dirty” oil, the catalyst will be silent - after all, to activate its work, it requires special conditions, temperature and pressure. But they are just in the active zone of the friction units. So, check this out too!

The main problem that has arisen before us is where to get this catalyst? Our requests for help in this matter were answered only by Russian representation by MOTUL. It seems that only they, by the way, never exposed in cases of premature loss of oil, found it necessary to establish the truth! For this we sincerely thank them, and let them not consider our thanks as an advertisement for this company.

So, two options for the catalyst used in the production of hydrocracking base oil, we have. We turned large granules of catalysts into a fine-grained powder of the desired fractional composition - such that it would fly through the pores of the oil filter. These powders were mixed with oil, and after half an hour they saw - here it is, a harmful sediment!

This oil was poured into the next engine, intended for slaughter, and a cycle of its long knurling began. At first everything went well, but after twenty hours of testing they began to notice that the oil pressure was dropping. And the oil on the dipstick became noticeably thicker - all the more, they initially used very good “synthetics” 5W-30, against its background, the increase in viscosity was especially noticeable! It's strange - the viscosity is clearly growing, and the pressure is dropping ... Maybe wear has appeared? But somehow this process progressed too quickly. The motor withstood only 40 hours of testing, after which the pressure completely disappeared. Then - everything, as usual, an autopsy, measurement, inspection.

The first thing that caught my eye was that from four liters of oil initially poured into the engine, only one and a half liters merged from it as a result of tests! And this is - in just 40 hours of very moderate modes, in terms of equivalent - less than 3000 kilometers! And the oil was terribly black. Measurements of engine parts did not reveal serious wear, although it was noticeable - the bearing shells and crankshaft journals were somehow very well polished. It is also clear - the catalyst powder worked as an abrasive. So why did the oil pressure drop so much? The presence of some solid agglomerates in the pallet immediately caught my eye, which sat firmly on the walls. These, apparently, were the very "harmless" according to the authors of the ill-fated letter "associations of fine particles." But they were clearly less than the volume of the initial sediment in the oil filled in the engine. We also did not notice particles in the filter. This means that the main part of the powder introduced by us into the oil has settled in the channels! This is the reason for the loss of pressure in the lubrication system.

And what did the analysis of the physico-chemical parameters of the oil that worked with this “harmless” powder show? The viscosity of the oil, which was originally 11.2 cSt at 100°C, has increased to 17.9 cSt! That is, the oil, which was originally in the SAE-30 class, jumped to the SAE-50 viscosity class in 40 hours! The acid number increased by more than 2.5 mg KOH/g. Recall that in the last resource examination for 180 engine hours, oils increased their acidity by only 0.75 ... 1.0 mg KOH / g! The base number decreased less, and the deposits on the walls of the crankcase were, although more than usual. Moreover, the oil at room temperature was so thick that it did not want to drain from the walls - we have not seen this before. By the way, the picture that we observed in our experiment was suspiciously reminiscent of the one that was given out by one of the oils during our previous “semi-synthetic” examination.

So, according to some oilers, "harmless" catalyst powder in a relatively short time ruined the oil and finished off the engine. And in this case, alas, even the “capital” will not help him - after all, removing the plugs that clog the oil channels, judging by the structure of deposits in the sump, will be extremely problematic. By the way, some conscious dealers major automakers faced with a similar problem, without talking, they changed either cylinder blocks or the entire engine assembly.

The results already clearly show that neither automakers nor car owners are to blame for the troubles that have happened. After all, the thermal instability of some types of oil, leading it to polymerization during volumetric overheating, and the possible presence of an aggressive catalyst deposit in it, which is allowed by some oil manufacturers, are the most serious "punctures" of these companies.

Summing up, while intermediate. Of course, someone would like to hear a loud appeal: they say, do not buy oil from firms A, B and C! And buy D-oil: it never gets sick! But we did not look for the guilty switchman, but investigated the problem. In addition, ten thousand cars can happily run on company A oil, but ten thousand will be the first to get into an unpleasant situation. On the other hand, we technically competently substantiated the inconsistency of the on-duty attacks on the burdock driver. Moreover, we were able to find some possible reasons mass cases of accelerated death of oil and the engine as a whole.

We sincerely want to believe that oil and gasoline manufacturers will carefully study our conclusions: all motorists are waiting for this. In the meantime, we recommend using our recommendations on "Methods of Self-Defense", following which you can save the engine in a critical situation.

DROP SAMPLE

On any porous paper (optimally - a piece of filter for a coffee maker or at least a piece of newspaper) with oil dipstick cold engine, put a drop of oil. If it quickly spreads over the paper, forming several concentric circles, then the oil is alive. But if it does not want to spread and remains a black drop at the point of fall - urgently replace it!

CAN'T CHECK OIL? FIND A PIECE OF NEWSPAPER!

P.S. It goes without saying that in the course of one of the next examinations of oils, we will separately analyze their resistance to the atrocities we have uncovered. One direction of search is already clear: a new wave of failures was noticed after one of the well-known refineries started working after modernization - after all, a similar catalyst is used in the production of high-octane gasoline!!! But doesn’t it come into the oil with this outwardly quite conditioned fuel? And from another region, information came about an allegedly accidental coincidence of the death of engines according to the scheme we described with the use of fuel containing an exorbitant dose of methanol, which is strictly prohibited in our country. This also needs to be dealt with.

HOT? TRAFFIC JAMS? CHECK THE OIL!

SELF DEFENSE METHODS

To protect yourself from possible trouble, we repeat our recommendations once again:

1. Use only oils purchased from trusted stores. For scheduled maintenance, it is better to come with your oil canister. After buying it, let it stand for a while, and, if possible, see if there is sediment in the canister. Usually the sediment can be seen on the transparent measuring strip on the canister.

2. Make it a rule, even if your engine is not noticed in increased oil appetite, at least once a week to get under the hood and monitor the level and condition of the oil on the dipstick. You should immediately be alerted by a sharp increase in oil consumption, or its sudden dilution, or, conversely, thickening.

3. Be especially attentive to the oil in the summer, when standing in traffic jams for a long time, or during long-distance high-speed hauls. It is then that volumetric overheating of the oil is possible.

4. Adopt the so-called. " drop test» oils. Its essence and procedure are extremely simple. On any porous paper (optimally - a piece of a filter for a coffee maker, or at least a piece of newspaper) from the oil dipstick of a cold engine, drip a drop of oil. If it quickly spreads over the paper, forming several concentric circles, then the oil is alive. And, if it does not want to spread, remaining a black drop at the place of fall - urgently to the service station to replace it!

All impurities that enter the engine with the air entering for combustion, found in fuel or oil, as well as wear products of parts, can participate in the formation of deposits on them. The amount and composition of contaminants depend on the design, technical condition, engine operation mode, timeliness and thoroughness of the Maintenance. But especially big influence the intensity of high-temperature deposits formation is affected by the quality of the fuel burned and the oil used. In the standards, both for gasoline and diesel fuel, indicators are normalized that affect the formation of high-temperature deposits. Let's briefly review them.

in petrol and diesel fuel the dissolved state almost always contains resinous and tar-forming compounds, the amount of which depends on the type and composition of the fuel, the technology of its production and purification methods. During storage, especially under unfavorable conditions (poor sealing of tanks, the presence of sediments and water in them, storage at elevated temperatures), the amount of resins increases, sometimes significantly, then the fuel darkens, and in some cases deposits accumulate in it. A fuel that is heavier in fractional composition, for example, diesel, contains a greater amount of tar compounds, which leads to its incomplete combustion and significant accumulation of carbon deposits on engine parts.

Contained in fuel resin deposited V fuel tanks, on the walls of pipelines, jets of carburetor engines clog. Resinous compounds also accumulate on hot walls intake manifold carburetor engines, on nozzles of diesel injectors, on valves and the bottom of the piston, in the combustion chamber, in piston grooves, etc. With a large accumulation of soot, engine wear increases, the fuel combustion process worsens, its consumption increases, and sometimes the engine completely fails.

There are actual resins, i.e., those that are in the fuel at the time of their determination in a dissolved state, and resin-forming substances - various unstable compounds, for example, unsaturated hydrocarbons, which, under the influence of time, elevated temperature, atmospheric oxygen and other factors, turn into resins (they are often called potential resins).

Standards are normalized actual resin content. The essence of their determination lies in the evaporation of a certain amount of fuel by hot air at an elevated temperature (for gasoline 150°C, diesel fuel 250°C). The residue obtained after evaporation indicates the presence of actual tar, which is estimated in milligrams per 100 ml of fuel. For gasoline of various grades, it is up to 7-15 mg / 100 ml, and for diesel fuel - up to 30-60 mg / 100 ml.

If the content of the actual resins meets the requirements of the standards, the engines operate for a long time without increased resin and carbon formation. Often, during the operation of equipment, the content of resins in the fuel is much higher. It is proved that if it is two or three times higher than the norm, then motor resource carburetor engine is reduced by 20-25%, and diesel - by 40%. In addition, various problems occur during operation: valves freeze, nozzles coke, etc.

The tendency of gasoline to accumulate resinous substances(stability) is evaluated by the induction period, which characterizes the ability of gasoline to maintain a constant composition at right conditions transportation, storage and use. This indicator is determined in a laboratory installation during the artificial oxidation of gasoline (temperature 100 ° C in an atmosphere of dry and pure oxygen at a pressure of 0.7 MPa (7 kgf / cm2). induction period- this is the time in minutes from the beginning of gasoline oxidation to the active consumption of oxygen by it. For various grades, this value is in the range of 600-900 min, and for gasolines with a quality mark, it is 1200 min. The induction period of most modern brands is at least 900 minutes. As established by research, such gasoline can be stored for up to 1.0-1.5 years without fear of a noticeable deterioration in quality.

For carburetor engines the most characteristic is the accumulation of resinous deposits, which are found in gas sumps, on carburetor parts. When a combustible mixture is formed, resinous compounds cannot evaporate and are deposited in the suction pipe and on the valves. As a result, the valve stops closing and freezes. These resinous deposits cause various problems in the operation of the fuel supply equipment and the engine.

For diesels especially undesirable is the deposition of varnishes and deposits on the nozzles of the injectors, which violate the normal spray of the supplied fuel, and, consequently, its combustion. In the standards for diesel fuel, in addition to actual resins, coking capacity and ash content are normalized, the increased content of which causes intense formation of carbon deposits.

Great harm (not only the accelerated formation of soot, but also the rapid wear of parts of the fuel supply equipment and the engine as a whole) is caused by abrasive mechanical impurities entering the engine with fuel and air. According to the standard, the presence of mechanical impurities in gasoline and diesel fuel is not allowed. However, during storage, transportation, and handling operations, fuel is usually contaminated with dust and sand from the ambient air. Even in pure appearance fuel almost always contains some amount of impurities. Together with tarry and coke-forming substances, these foreign inclusions lead to an increase in high-temperature deposits. In addition, dust particles penetrating the engine accelerate its wear.

If the fuel contains abrasive mechanical impurities, then the service life of the pump high pressure depending on the contamination is reduced by five to six times. Abrasive reduces the service life of not only fuel supply equipment. When contaminated fuel enters the combustion chamber, mechanical impurities penetrate into the gaps between piston rings and cylinder liner, which leads to their increased wear and, as a result, to a drop in power, deterioration in efficiency, and the need for premature repairs.