The engine oil is black - what is the reason? Today, drivers practically do not diagnose the condition of their car. Meanwhile, careful attention to the "iron horse" can help avoid costly repairs. One of the most common signs that something is going wrong is a change in the color of the engine oil. If it was white when it was poured, then see what a wonderful transformation can take place. When the oil turns black, it cannot but alarm a novice motorist. The change in its color sometimes happens quickly.
A change in the color of the engine oil is a sign that something is wrong with the car.
Reasons why engine oil turns black
Under certain conditions, the oil may change its color. If the motor is in working condition, the cleansing properties of the oil itself may be the cause. Today, manufacturers are striving to create a universal tool that would be suitable for everything at once. Therefore, various additives are added to modern oil that can increase the life of the engine.
To distinguish the original oil from a fake, you need to pay attention to the label, which contains all the manufacturer's data.
Among the numerous components of the product, special substances stand out that can dissolve those deposits that accumulate in the "heart" of the car. When the oil is changed, the elements that act as cleaners are simply removed. If the owner of the car does not notice any problems with engine operation or fuel consumption, black oil does not pose any danger. Maintain its normal level, and it, in turn, will work properly and clean the engine with high quality.
The oil in the engine may turn black when the engine is malfunctioning. Then you can smell the burning smell characteristic of this breakdown. In the power unit, piston oil scraper rings could wear out. Oil burns while driving when the engine is running. The owner of the car can check the car for the above problem at any car service. An indirect cause is the phenomenon of “eating” oil by the engine. The problem can be solved if you add oil until the moment when the replacement is made.
The above reasons clearly demonstrate that the oil in the engine is black if the product used is of high quality. And the motorist should be alerted by a white substance that does not change its color throughout the entire period of operation. This motor tool does not perform a cleaning function, and deposits accumulate in the motor.
If you pour expensive oil from trusted manufacturers after it, it will quickly become dark in color. He will have to deal with all the dirt that remains from a low-quality product. An ignorant motorist interprets what is happening in his own way. Having changed the usual cheap brand of oil for an expensive one, after 1,000 km he notices that the color has changed. The car enthusiast thinks he bought a cheap fake.
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How does oil turn black?
Some oils turn black almost immediately after pouring, while others need some time. The speed of the browning process is influenced by 2 main factors:
- How clean is a car engine. The presence of substances that can contaminate the lubricant is important.
- The number of alkaline additives that are part of the engine oil.
Considering the first case, it can be noted that the car oil will turn black quickly. Previous operation left behind negative consequences in the form of various deposits. The owner of the car needs to constantly monitor the condition of the oil filter. If the oil passages are clogged, the motor will become unusable. Therefore, the oil filter needs to be changed periodically. Good quality car oil retains its detergent and lubricating properties for a long time. Suspended particles settle in the filter, due to which the engine is gradually cleaned.
It is recommended to clean the engine in stages. Aggressive additives can cause the most unpredictable consequences. Auto-lubrication of working grades has an optimal viscosity. If you use normal flushing oil, then the engine wears out faster.
Sometimes the grease turns black if gas breakthrough occurs in the crankcase. Car overhaul will help to solve the problem in the best way. Before it is carried out, the following actions will help extend the life of the unit:
Adding oil to the engine to maintain the required level.
- change of piston rings;
- boring of liners for cylinders, taking into account the repair dimensions.
The described situation is typical for older engines. The problem costs the motorist “a pretty penny”. The engine consumes more fuel and literally devours oil. Here you will have to seek help from a reliable car service, where knowledgeable mechanics will fix the breakdown. A major overhaul will return the car to its former performance.
An experienced motorist can easily find out when it's time to change the oil, depending on the car's mileage and its general behavior. When the oil turns black very quickly, however, it is consumed within the normal range, then it is possible to change the lubricant more often. And change the oil filters twice. Over time, the engine will become cleaner, which will affect the rate of blackening of the lubricant. The color change process will become slower.
The desire to write an article on this topic arose thanks to two car service customers who, without saying a word, arrived on the same day in almost identical cars (Honda Accord CF3 and CF4) and asked very similar questions. In the first case, it was not even a question, but almost a claim that sounded like this: “Why did the oil that you poured into me turn black almost immediately?”. And to my phrase “and what bothers you”, I heard: “Experts told me that this is very bad and the oil is bad.”
In the second case, the client was not so categorical, and was worried about the condition of the engine, because the oil filled in 2000 km ago turned black, and, as it seemed to him, smelled of burning.
If in the first case we had to get involved in a short argument, which did not end with anything and everyone remained with their own opinion, then in the second, we reassured the person by showing him the condition of the oil on one of our cars standing nearby, showing him a similar picture.
Nevertheless, two cases are already a trend, so we decided to tell everyone about why the oil turns black, is it good or bad, and most importantly, what does it depend on, and what are the side effects of this property.
So why does engine oil turn black?
Let's start from the very beginning, that is, with oil. Any modern engine oil contains a lot of different additives aimed at achieving different goals during engine operation. These are additives to reduce friction, and additives to change the working properties of the oil at different temperatures, and many others, among which there is a special additive that regulates the “base number” of engine oil. Alkali, it turns out, is an essential element that neutralizes acids that enter (during engine operation) into the oil system, and also counteracts deposits in the engine, removes dirt, varnish deposits and other “nasty things” that occur during engine operation.
What happens to the engine if the engine oil has a low amount of alkaline additives? The answer is simple - the engine wears out faster and becomes contaminated with all kinds of deposits. And the more these deposits, the harder it is for the engine to work - firstly, where the “dirt” has fallen, it is much more difficult for the oil to get through and starvation begins (hello to K-motors!), Secondly, the temperature regime of the engine is violated, since “ fur coat” does not allow heat to escape. The consequences of this are local overheating, destruction of engine elements (camshafts, rockers, cranking of liners).
By the way, a similar situation occurs if you do not change even highly alkaline oil for a long time. Over time, the alkaline additive begins to age (and this happens very quickly, and the more clogged the engine, the faster it happens), and the quality of protection against dirt decreases. This process can be compared to washing clothes. If you use a very good washing powder, but do not change the water, the first tab of laundry will be washed well, the second one will be worse, the third one will be even worse, and you may simply not see the fourth tab in the dirt that you get.
Why do different oils turn black at different times? There are two answers - the first one - your car has a very clean engine, and there is simply nothing to pollute the oil. Second, there are few alkaline additives in your engine oil.
Is it bad or good?
This question lies at the same time in the field of psychology and practicality. As practice shows, eternally clean motor oil gives people a feeling of deep moral satisfaction. Experienced motorists (which they generously and free of charge pass on to the younger generation) are sure that good oil should not darken at all, well, or only closer to 10,000 mileage. Where does this opinion come from? From past! Once upon a time, when oils were not at all of the same quality as they are now, good oil differed from bad oil, among other things, in the speed of its pollution. And this factor (the blackness of the engine oil) was one of the key indicators of the need to change it. That is, the oil has turned black - that's it, it's time to change it. And very cheap oils turned black after 500 kilometers, so motorists did not like them - who wants to change the oil every week? It is worth noting that oils in those days turned black not at all due to the presence of additives, but precisely because of their own poor quality, so the problem of those times is understandable to us. Another question arises - is this ratio (dark oil - bad oil) correct in terms of the quality of modern products and the condition of the engine? Our opinion is no, it is wrong.
Constantly clean modern engine oil does not mean its high quality, and not that the engine of your car is clean. Rather, on the contrary, this suggests that the oil is not doing its job of keeping the engine running and protecting it from harmful wear products.
The fact is that the darkened oil, which “took” these same products into itself, “binds” them, as it were, and prevents them from settling on the surface of the engine elements, and also prevents acid “precipitations” from contacting metal parts, causing their increased wear. and corrosion. "Eternally pure" oil suggests that this function is simply not being performed. And although seeing a clean drop of oil on the dipstick is always nicer than a dirty one, from the point of view of caring for the engine, this is wrong.
Another thing is why the oil darkens at different time intervals.
What determines the rate of darkening of the oil in the engine?
In our opinion, it depends on the internal state of the engine itself, and on how high the ratio of alkaline additives is in the oil that you use.
If, for example, the recommended oil change intervals are not observed at all, or poor (cheap) engine oil is used, deposits accumulate in the engine and settle on metal parts.
The more dirt in the engine, the faster the engine oil will darken, which will begin to “eat off” this dirt from engine parts. Moreover, this process will be the more intense, the more alkaline additives are contained in the oil.
That is, if the motor has even an average degree of pollution, and the oil is low-alkaline, then it will slowly wash it all away. And if the oil is highly alkaline, then it will turn black after some 200-300 km. The more dirt there is in the engine and the more “alkali” there is in the oil, the faster it will turn dark.
What side effects can this oil have?
In fact, as such, modern blackened oil does not have any side properties. The high-alkaline oil that has taken on the dirt, in principle, continues to work in the engine during the entire replacement period.
The only feature of high-alkaline oils can be called a relatively short service life (5,000 - 7,500 km). As a rule, high-alkaline oils do not have strong anti-aging additives, so their long-term operation (10,000 km or more) in the Russian climate is not recommended. Yes, and the oil itself with strong detergent properties will not work so much, rather, it will burn out in the engine earlier, from old age.
Thus, we can draw the following conclusions.
First, the darkening of modern quality motor oil is more “good” than “bad”. So it works, and launders deposits in the engine of your car.
Secondly, the intensity of darkening of the oil depends on the condition of the car's engine. If the engine is dirty, the oil will turn black faster, if it is clean, it will turn black more slowly.
Thirdly, high-quality, highly alkaline engine oil, as a rule, cannot work in the engine for too long intervals between replacements - the optimal mileage for such an oil is 5,000 - 7,500 km.
Therefore, if the engine oil in your car's engine quickly darkened after a change, don't be alarmed - it works, cleans the engine, does everything it needs to make it work longer. Do you want to help him? Just change your oil more often.
Honda waterdam.ru.
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Blackened motor grease
Many owners of various car brands ask the same question in car services. They do not understand why the motor oil running in the car engine turns black so quickly.
Someone immediately begins to make claims about the fact that only low-quality grease turns black so quickly. Someone does not behave so categorically, but worries about the condition of their engine, worrying about the fact that the recently filled car oil turns black literally before our eyes, while the car owner can even smell burning.
It is practically useless to argue about this, since the reasons for such a darkening of the lubricating fluid can be very different. It is far from always that car oil turns black as a result of poor quality or engine malfunctions.
However, such situations are quite common, so they should be considered in more detail. Below we will try to figure out why the darkening of the oil occurs, as a result of which it darkens, and what the consequences and side effects can be.
Reasons why oil can turn black
It is best to start from the very beginning - directly with automotive oil. The composition of any modern lubricating fluid contains a large number of various additives. They are used to achieve various goals during the operation of the oil. They include additives to reduce friction, additives that change the operating temperature properties of the oil, and many other auxiliary substances.
One of these additives in the lubricant is responsible for regulating the "base number" that engine oil has. It turns out that the alkali contained in it is a vital element. It neutralizes acids that penetrate the oil system during operation, and also prevents the formation of deposits in the engine, removes varnish deposits, dirt and other debris.
Additives improve lubricant properties In the case when alkaline additives are contained in the oil in a small amount, the motor begins to wear out faster and become clogged with various deposits. An increase in the amount of such deposits leads to a complication of the operation of the engine for two main reasons:
- In places of such pollution, the passage of oil becomes much more difficult, which leads to the so-called "oil starvation".
- There is a violation of the temperature regime of the motor, since deposits do not allow heat to escape. The consequences of this are local overheating, clogging of oil channels and the destruction of various engine elements, such as camshafts, cranking liners, rockers, etc.
It should be noted that a similar situation can also arise in the case of long-term use of high-alkaline oil without replacement.
Over time, aging of the alkaline additive occurs. It is carried out very quickly and accelerates as the engine becomes clogged, resulting in a decrease in the quality of protection of the motor from dirt.
Darkening is quite natural
Speaking about why blackening occurs, a few nuances should be clarified. First, darkened and blackened oil are completely different things. In addition, the reason that the car oil turns black quickly enough does not always lie directly in the car engine or in the insufficient quality of the lubricant. In fact, it is much worse if, after a certain period of operation, the car oil in the engine is just as clean. In this case, we can assume the presence of various impurities in the lubricant, making it simply useless.
open motor auto Simply put, the lubricant moves in the motor in a vicious circle. That is, the oil pump is pumped from the crankcase and driven through the channels. At the same time, it lubricates the engine parts, the waste is removed, and the excess settles again in the crankcase. It turns out that the same lubricating fluid constantly circulates through the system. There is nothing surprising in the fact that it gradually becomes darker.
The operating temperatures of the lubricant in the engine should also be considered. During its operation, the oil can heat up to 100-120 °. Such a high temperature not only allows you to create a lubricating effect, but also ensures the removal of carbon deposits from the internal combustion engine elements. It is as a result of this that the lubricant darkens, experts call this phenomenon “oil work”.
If, after a long period of operation, the oil remains uncontaminated, it means that it does not contain cleaning additives. In this case, all waste, including slag, impurities and soot, is deposited on the engine elements. In this case, it is advisable to remember this brand of oil so that you never buy it again.
Blackening - the norm or not?
Another thing is if the grease turns black, and does not darken, and begins to resemble fuel oil. This can be determined with an oil dipstick. If black stains remain after wiping the dipstick, it means that the lubricant is burning in the engine.
A similar problem most often occurs as a result of wear of the piston group. In this case, excess fuel that has not burned out in the engine cylinders penetrates into the lubricant. As a result, its composition changes, which makes the oil unsuitable for use. That is, in this case, rapidly blackening oil is a kind of indicator of the presence of internal combustion engine malfunctions, including an increase in fuel consumption and a decrease in the power characteristics of the motor.
Another reason for blackening may be overheating of the oil in the motor. In the case of frequent operation of the engine at high speeds and an incorrectly selected viscosity, oil begins to boil. All impurities contained in the hot liquid dissolve, forming a single mass. As a result, the oil ceases to be as dark as usual, turning into black.
It is necessary to immediately replace such a lubricant, since it no longer has cleaning properties. Moreover, it can be the cause of malfunctions of the oil pump and other units.
How does the blackening process take place?
Why do different oils turn black at different times? In answering this question, two main factors can be considered:
- The cleanliness of a car engine, that is, the presence of substances in it that can contaminate the lubricant.
- The amount of alkaline additives contained in the engine oil used.
Let us consider in more detail what to do with both reasons why a motor lubricant turns black quickly enough. In the first case, the engine may be heavily contaminated with various deposits that have accumulated in it during the previous period of operation. This can be considered normal, although the oil channels may gradually become clogged, after which the motor may fail. In this case, it is recommended to replace the oil filter first. It is advisable to do this several times throughout the entire period of working out the oil, while it retains its lubricating and detergent properties. In this case, suspended particles will settle in the filter, which will lead to a gradual cleaning of the engine.
Flushing the motor It is better to clean the engine gradually, rather than using aggressive additives to wash the motor. Any aggressive component that has entered the lubrication system, if subsequently mixed with a working lubricant, can cause unpredictable consequences. In addition, even good flushing oils have a much lower viscosity than performance grades of auto lubricants, which leads to engine operation with increased wear. Therefore, it is advisable to purchase engine oil in advance and reduce the length of the service run between replacements.
In the second option, the lubricant can turn black quite quickly due to gas breakthrough in the crankcase. At the same time, there is a significant increase in fuel consumption and an inappropriate appetite of the engine for motor oil. The solution to this problem is, in fact, a major overhaul. In addition, the replacement of piston rings and boring of cylinder liners for repair dimensions helps to partially solve the problem. It should be noted that such a solution, as well as the problem situation itself, is more typical for old and worn out engines.
In general, you should be guided by the mileage of the car and its general behavior. If the oil simply turns black at a high rate, but is consumed within normal limits, then you can try to replace the lubricant itself more often and change the oil filters twice during the cycle. In this case, the engine can gradually clean up, and the blackening of the lubricant in it will slow down.
Consequences
The question of whether blackening of grease is a bad sign is both psychological and practical. Practice shows that people get deep moral satisfaction from a pure motor lubricant. Experienced motorists often believe that good quality car oil should not turn dark at all, except perhaps closer to 10,000 kilometers.
Bad lubrication will ruin the motor This opinion is rooted in the past, when the quality of auto lubricants was completely different. A good motor lubricant then differed from a bad one, among other things, by the speed of its pollution. And such a factor as the blackness of the lubricant was considered one of the most important indicators of the need for its replacement. The cheapest oils turned black after 500 km, so car owners treated them negatively - few people like to change the lubricant every week.
It should also be noted that motor oils in those years could turn black not even due to additives, but precisely as a result of the poor quality of the lubricants themselves, so the problems of those times are quite understandable. At the same time, a doubt arises as to whether such an attitude is fair for assessing the quality of modern products and the condition of engines?
The constant purity of modern motor oils may not speak of their high quality and not the cleanliness of the car engine.
Most often, the opposite conclusion can be drawn: the car oil is unable to cope with one of its most important duties. It simply cannot keep the engine running and protect it from harmful wear products. The reason lies in the fact that darkening oil "absorbs" all these products. At the same time, it “binds” them, as it were, not allowing them to settle on the surfaces of the motor elements. In addition, at the same time, acid “precipitation” does not come into contact with metal parts in any way, which prevents increased wear and corrosion of these elements.
Consistently clean oil is an indication that this function is simply not working. Even though a clean drop of grease on the dipstick always looks nicer than a dirty one, this is a disadvantage in terms of engine care.
About the speed and consequences of darkening
It should also be considered why the oil may darken at different rates. First of all, this is influenced by the internal state of the engine itself, as well as the value of the coefficient of alkaline additives contained in the lubricant used. So, in case of non-compliance with the recommended oil change intervals or the use of a bad (cheap) substance, deposits begin to accumulate in the engine, settling on metal elements. The more such dirt settles in the engine, the faster the oil begins to darken, “eating away” deposits from the motor elements.
The amount of alkaline additives directly affects the intensity of removal of various dirt.
Oil change Thus, even in the case of an average degree of engine fouling, the use of low alkaline oil leads to delayed removal of deposits. At the same time, highly alkaline motor oils can darken after 200-300 kilometers. That is, the amount of dirt in the motor and alkali in the lubricant together have a direct effect on the rate of darkening.
If we talk about the side effects of modern blackened oils, then they are absent as such. A grease with a large amount of alkali, which has taken on the dirt, is, in principle, able to continue working in the motor throughout the entire replacement period. The only feature of such motor oils is their relatively short service life, averaging from 5 to 7.5 thousand kilometers. In addition, high alkaline oils usually do not contain strong anti-aging additives. In this regard, their long-term operation, exceeding 10,000 km in the climatic conditions of our country, is not recommended. And the oils themselves, which have good detergent properties, are not able to work so much - they are more likely to burn out in the engine from old age.
Summing up the above, three main conclusions can be drawn:
- If modern high-quality engine oil darkens, this is more a plus than a minus. At the same time, it performs its task and washes away deposits from the engine.
- The rate of blackening of oils depends on the state of the engine. If it is clean, then the oil will turn black slowly, if it is dirty, it will turn black quickly.
- High-quality high-alkaline motor oils are most often not able to work for too long run intervals. They are recommended to be replaced after every 5000 - 7500 kilometers.
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 repairs. 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 engine will react to its small amount by lighting up the control lamps on the dashboard and sound alarms. 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 a high sulfur content in the fuel, or the presence of a large amount of tar in it. Let's say right away that, apart from sulfur, everything else, according to the 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 the idle cylinder will fly into the crankcase in large quantities.
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. The alkaline 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 the initial 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. In their opinion, the picture that we are seeing, that is, a sharp increase in oil viscosity, may be associated with 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 from a very well-known company for topping up, suddenly discovered in it ... an incomprehensible sediment! And from the answer of a technical specialist of the Russian representative office of this company, who, to our request for an explanation of the situation, literally uttered the following: “I hereby inform you that a small amount of sediment is allowed in motor and transmission oils. 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. They do not affect the performance characteristics of commercial oil and, subsequently, in the process of operation, they again turn 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? Only the Russian representative office of MOTUL responded to our requests for help in this matter. 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, we have two options for the catalyst used in the production of hydrocracked base oil. 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 of large automakers who encountered a similar problem changed either cylinder blocks or the entire engine assembly without talking.
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 managed to find some possible causes of mass cases of accelerated oil and engine death in general.
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 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. 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. "drip test" of oil. 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!
It is not difficult to answer the burning question of car owners about why the oil in the engine quickly turns black. The lubricating mass gains and retains the exhaustion of burnt fuel and metal oxides of rubbing surfaces. However, many have difficulty imagining the process in which engine oil is involved. Seeing that it is getting dark, motorists perceive this as a bad sign and try to find out the reasons. The main concern is the use of low-quality lubricant.
Why does a car need lubrication?
To get rid of a false alarm, you need to figure out how the oil works in the engine. In gasoline and diesel power units, lubricant is a universal product. It not only serves the sliding of surfaces, but also cleans them from the inevitable technical dirt. For this purpose, the lubricant contains various additives that are responsible for correcting the base number inherent in the product.
If the engine oil is dark, this means that the alkali is doing the necessary work. The substance neutralizes acids, eliminates deposits of dirt and soot. Naturally, the lubricant quickly darkens in the process of continuous cleaning of engine components. The invariance of the original color of the lubricating and cleansing mass, on the contrary, indicates its insufficient effectiveness. That is why, after seeing a clean lubricant after a long operation, the motorist should be alert. It is likely that there is a fake that does not perform the main functions. It is precisely because low-quality counterfeit is useless and does not absorb dirt, respectively, the lubricant does not darken.
Often the causes of mud deposits in vehicle components and, accordingly, their accelerated wear lie in the low content of alkaline additives. Conversely, a quickly darkened oil in a gasoline or diesel engine indicates the sufficiency of the base number and its cleaning ability. Proper lubrication will help to avoid two main causes of malfunction of the unit:
- Oil "starvation" due to the appearance of contamination zones that complicate the penetration of the oily liquid.
- Violations of the temperature regime of the engine, as mud deposits prevent heat removal. Local overheating as a result will lead to the destruction of the camshaft, rotation of the liners, and other malfunctions.
However, it should be recognized that problems can also arise with a high alkali content - if the engine oil is not updated on time. The additive quickly becomes obsolete, struggling with abundant contamination, which, in turn, reduces the quality of cleaning.
Turns black - it means it works
The automotive oil system is a closed circuit. From the crankcase, the oil pump drives the lubricating fluid through the channels of the system. Making a full turn, the engine oil picks up soot, oxides and returns to the crankcase. That is, the product permanently circulates through the dirtiest "back streets" of the internal combustion engine (internal combustion engine). It is quite natural that over time the grease turns black.
In this case, one should not forget about the temperature regime in which the oil is located. Its temperature often reaches over 100°C. High heating contributes to the effective lubrication of the nodes and the thorough removal of carbon deposits - this is another reason for darkening. This color change is called "oil work". From this we can conclude that if the oil does not darken after a long run, it is deficient in cleaning additives. Naturally, all oxides, deposits and other slags remain inside the engine, settling on its nodes. In this case, you just have to exclude a low-quality product from your purchases.
Causes of blackening
Is the oil dark or black? Such conditions can cause various causes, which are not necessarily hidden in the low quality of the lubricant or excessive contamination of the automobile engine. Engine oil, which not only turned dark, but became a black liquid resembling fuel oil, indicates its combustion in the engine cylinders. To find out, wipe the dipstick with a clean rag. Black marks left on the fabric in the form of soot will confirm the burnout of the grease.
This problem is caused by the wear of the piston group. Part of the unburned fuel penetrates the gap between the cylinder and piston, mixing with the lubricant. In addition, the weakness of the oil scraper rings of the piston allows some of the oil that burns out with the fuel to remain on the cylinder walls. In this case, the presence of black oil warns the car owner of a problem that can lead to increased fuel consumption and loss of engine power.
An equally common reason for the black color of the lubricant is its overheating inside the engine. Due to the wrong choice of oil viscosity characteristics and during prolonged operation of the engine at high speeds, the lubricant boils. The additives break down, turning the once-clear liquid into black oil. In this case, it is better to quickly change the lubricant. After all, it has already lost its consumer properties and can only harm the oil pump, filter and other components.
How to solve a problem
How to prevent darkening of the oil or get rid of the consequences of this problem? Here are a few main factors why auto lubrication darkens very quickly:
With improper care, the contamination of the automobile engine increases up to the clogging of the oil channels. This state is unsafe for the operation of internal combustion engine components and cylinders. Therefore, immediate flushing and replacement of the oil filter is recommended. It is even better to change the filters several times during the prescribed run cycle, which contributes to cleaning. Standard cleaning should preferably be carried out without the use of aggressive flushing agents.
Chemically hard components partially remain inside the oil system - this is why the oil turns black. In addition, flush oils have a much lower viscosity level, which cannot be considered beneficial when mixed with a newly filled "native" lubricant. As a result, the engine is threatened with increased wear. It is better to shorten the run cycles between service oil changes.
The oil turns black due to a breakthrough into the crankcase of exhaust gases. This dramatically increases the consumption of fuel and lubricants. Such a problem may require major repairs. The problem is partially solved by boring the cylinders and replacing the piston rings. However, such troubles are found, as a rule, in older cars with impressive engine wear.
During a service run of the engine, engine oil, blackening due to the abundance of alkaline additives, is recommended to be changed several times along with filters. After gradual cleaning of the unit, the color of the lubricant returns to normal. However, it should be remembered that the operation of the car in normal mode involves the change of high-alkaline oil every 5-7 thousand km.
If the engine oil quickly becomes dark, do not be afraid. This means that it is doing its job - it cleans the engine of deposits. Change the lubricant in a timely manner and buy only the original product.
