How to determine the cause of engine oil consumption

The main causes of excessive engine oil consumption

To slow down the wear of car engine parts and components, the design provides for the use of a closed, sealed oil circuit. By moving, the lubricant helps lower the temperature of all moving elements of the motor that are subject to friction.

Increased oil consumption in a car engine is the most common problem for many motorists. There is a well-known term among car enthusiasts - the engine eats oil. The most common symptoms are the appearance of large characteristic spots under the car, a large amount of smoke exhaust coming out of the pipe, and foaming of the coolant.

Oil consumption when the engine is running properly

The nominal amount of oil consumed by a working car is from 20 to 40 grams per thousand kilometers. Oil consumption increases and can reach 200 grams per thousand km when the machine is operated in difficult conditions. But if the consumption increases to glasses and even liters, you should understand that there are problems with the engine. In these cases, it becomes necessary to pour oil into the engine sump more and more often. Basically, the lubricant evaporates due to exposure to high temperatures.

Factors influencing increased oil consumption

When identifying the causes of an oil leak, the following factors are considered:

Increase in temperature inside the engine.
The viscosity of the lubricant does not correspond to a given car model; what kind of oil is used is of great importance.
Oil seals have increased wear.
Faulty valves and clogged passages in the positive crankcase ventilation (PVC) system.
Loosening the fastening bolts.
Failure of sealing parts.
Leakage in the cylinder head gasket.

When the engine overheats, the valve stem seals are damaged and scuff marks appear on the cylinders. When the temperature is brought to the boiling point of the engine, irreversible changes occur in the engine, requiring expensive repairs.

Incorrectly selected viscosity causes mechanical damage to engine components and parts, which leads to lubricant penetration into the combustion chamber.

Faulty PVC valves can cause increased pressure, rupture of seals and seals. The leak continues despite replacing the lubricant.

The mounting bolts of the overhead parts require periodic tightening to prevent incipient leaks.

Primary diagnosis of increased oil consumption

Warning signs may not appear simultaneously with increased oil consumption. There are different stages of flow disturbance:

Moderate consumption of lubricant - in this case, it is not entirely clear whether the engine is consuming oil in excess of the established standards.
The engine consumes lubricant intensively.
Periodic increased consumption - intermittently, leaks may begin after the car has been driven for a long time.

Determining the causes of increased lubrication consumption

In order to understand why the engine eats oil, it is necessary to study the nature and frequency of occurrences of alarming events and take into account additional factors that have appeared. This defect may be caused by the following reasons:

Combustion of lubricant together with fuel caused by worn piston rings.
Leakage through hardened gaskets and cracks in them.
Penetration of lubricant into the cooling system through cylinder head gaskets that have lost their properties.

Diagnosis of oil leaks

There are times when it is difficult to determine why the engine consumes oil in large quantities. The exhaust pipe does not smoke, there are no traces of oil in the exhaust, there is not a single sign of combustion of the lubricant in a running engine, and its consumption is clearly increased.

How to determine a defect? If the engine consumes oil, but does not smoke, then the reasons lie in the following components and systems:

the presence of leaks in the lubrication system or the oil filter is simply loosened - characteristic greasy spots form under the car;
it is necessary to replace a worn PVC valve that interferes with the operation of the ventilation system;
mechanical damage to the motor housing, in this case you need to check the overall compression;
worn valve seals - their diagnosis and replacement should be carried out by experienced professionals;
damage to engine gaskets and sealing elements;

Increased foaming of the coolant and its dark brown coloration indicate the following problems:

one of the cylinder gaskets has become unusable and needs to be replaced;
cracks appear in the cylinder head - you need to remove it, restore it or replace it with a whole one;
lubricant gets into the cooling system, which requires repair or replacement of the oil cooler.

If the engine began to consume oil intensively, blue smoke began to pour out of the exhaust pipe, and the car’s power dropped significantly, the reasons are the following problems:

the forced ventilation system of the PVC crankcase is clogged, which led to the suction of lubricant into the engine, in this case it is necessary to replace the PVC valve;
mechanical damage to the engine, allowing material to penetrate into the combustion chamber;
the entry of remnants of a destroyed catalytic converter into the combustion chamber, leading to mechanical destruction of the piston groups, as well as cylinders;
wear of the rings and grooved cylinder walls, which leads to expensive overhauls.

Measures to eliminate increased lubricant consumption

What to do when the reasons have been established that the engine has begun to consume oil and grease intensively?

Eliminating engine oil leaks is most often accompanied by complete removal and disassembly of the engine . Dismantling and disassembly is carried out in accordance with the recommendations of the instructions drawn up at the manufacturer. Only such operations will lead to the fact that the motor will no longer consume lubricant.

If there is a noticeable change in the shape of the cylinders, they must be replaced with new ones. Worn oil scraper and compression rings, damaged piston, and turbocharger bearings must also be replaced.

If lubricant leaks through the cylinder head gasket, it must be removed and replaced with a new sample. But you should not undertake this work yourself without appropriate training and experience, since these operations require high qualifications and skill.

When using a lubricant that has an unsuitable viscosity for a car of a given brand, it is necessary to completely replace it. You need to fill in new oil that matches the car model. To carry out a set of works to replace the motor fluid, it is necessary to wait until its temperature drops in order to avoid skin injuries. The oil filter will need to be replaced with a new one that matches the make of the car in all respects.

Black smoke coming out of the exhaust pipe indicates the combustion of lubricant in the engine cylinders. To eliminate this defect, you can independently adjust the ignition in the car, following the instructions.

To avoid costly repairs, many car owners use special additives in their engine oil. Judging by consumer reviews, they help improve the properties of lubricating fluids, reduce their consumption and leakage, and increase the performance of engines. Additives with anti-wear and antioxidant properties are especially popular.

Increased engine oil consumption: symptoms and causes

Most car enthusiasts encounter the problem of increased oil consumption while operating a vehicle. The reasons for this behavior of the motor may be different. Below we will talk about what circumstances cause the oil to burn and how to prevent a major overhaul of the power unit.

Why does the engine start to eat oil intensively?

We should start with the fact that among internal combustion engines there is not a single one that does not consume oil during operation. This circumstance is inherent in the principle of their operation and motorists just have to put up with it. Even an engine installed in a car that has just left the showroom will consume a small amount of oil. But as the vehicle’s mileage increases, the oil consumption parameter will only increase. A new engine in a standard city car for a range of seven thousand kilometers on average consumes no more than 100 grams of lubricant.

The nature of excessive oil consumption by the engine can be determined by the intensity of the problem. The power unit can “eat” lubricant:

in small volumes, slightly exceeding the norm specified by the manufacturer;
in volumes significantly exceeding the norm;
with enviable consistency and in the same quantity;
periods: consumption will either be within the normal range or exceed it.

The main reasons for burning oil

There may be several reasons that influence increased engine oil consumption. Therefore, it is worth reading and understanding them in detail.

1. Problems with the operation of the cylinder-piston group

Stain on the piston

Often the basis for problems with increased lubricant consumption is the deplorable condition of the cylinders, pistons and their rings. If the engine is working properly, then when the operating temperature is reached, the gap between the cylinder walls and the piston becomes minimal. Accordingly, the rings will fit as closely as possible to the cylinders. As the vehicle is used, the cylinder changes shape. At the point where the maximum linear speed of the piston is reached, that is, in the middle, the diameter of the cylinder will gradually increase. Due to the lateral load coming from the connecting rods, wear will be uneven. Thus, the cylinder becomes oval-barrel-shaped. With such deformation, the rings wear out and lose the ability to track the shape of the cylinder walls.

In the event of a significant deterioration in the performance of the piston system, the gaps located between the cylinder wall and the oil scraper rings increase (stuck rings). For this reason, the ring does not completely drive off the oil, and the liquid remains on the walls. Once the lubricant enters the combustion chamber, it becomes black smoke and is released through the exhaust system. These processes are the reason why vehicles with worn-out engines become so “smoky.”

High consumption of motor lubricant can be accompanied by not only black, but also blue exhaust. To be sure of the exact cause of the phenomenon hidden behind the increased consumption of lubricant, it is worth using a gas analyzer. There is also a popular way to check, which consists of covering the exhaust pipe for a short time with a clean piece of paper. The presence of grease stains on paper in the exhaust indicates the presence of oil.

Oil can also enter the combustion chamber and come out of it as black smoke due to wear of parts in the friction pair, consisting of the valve and its guide. During constant operation of the machine, the valve play at the seating point increases. Next, this part will break the oil seal, which includes an oil seal that collects excess oil.

If a block made of aluminum is installed in the engine, then with constant overheating of the engine, the process of warping of the cylinder block will begin. This will cause increased lubricant consumption by the power unit.

The most unpleasant situations when oil burns become noticeable to the car owner are severe damage to the cylinder-piston group. These include, for example, a broken ring.

2. Problems with the cylinder head and piston ring wear

The only problem area in a working engine, through which lubricant manages to get into the combustion chamber, is the valve guides. In order for this friction pair to function properly, it must be provided with oil, even though modern bronze or cermet bushings can function with a small amount of lubricating fluid. The valve stem seals limit the amount of oil that remains on the valve stem. But these structural elements are also subject to wear and tear over time. The result is a gradual increase in the amount of lubricant remaining on the valves. And if this feature on the exhaust valve is almost invisible, then from the intake valve excess oil is very quickly carried away by air into the combustion chamber.

The main symptom of wear on the valve stem seals is increased smoke when re-gasping. This happens due to the fact that the throttle valve closes at increased speeds. In this case, the vacuum value in the intake manifold is at the maximum limit. Accordingly, the oil will, in the literal sense of the word, be sucked through the guides into the cylinder. If you do not pay attention to the problem, the guides will wear out and transverse play of the valve will occur. But even replacing with new valve stem seals will not help solve this problem.

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Among the reasons for increased wear of valve stem seals and rings, we highlight:

high mileage;
constant overheating of the power unit;
incorrectly selected viscosity or type of lubricant;
incorrectly selected additives;
constant over-gassing;
daily use of the motor at maximum power;
cold start.

3. Problem with valves or channels of the crankcase ventilation system

The main task of the crankcase ventilation system is to maintain a low pressure level in it. This is the only way to reduce lubricant leakage through the seals. In order for the piston rings to function correctly, the crankcase gas pressure must be a certain value. Relief of excess pressure is assigned to a special bypass valve. If it fails, for example due to jamming or contamination with soot, the pressure value will increase, and it will become difficult for the piston rings to remove lubricant from the walls with the same efficiency. This causes an increase in engine oil consumption.

4. Problem with wear of cuffs, gaskets and seals

It’s worth starting with the simplest and least expensive problem, which is a leaking crankshaft oil seal. This defect is easily detected by the car owner after parking the car overnight. If there is a puddle or even small oil smudges under the car, then the motorist needs to urgently replace the oil seal. In addition, a visual inspection of the engine compartment will help identify the problem. If there are traces of oil, we can conclude that the edges on the crankshaft oil seal are worn. There are many reasons for this defect. However, the most common is operational wear. Over time, the seal material, that is, rubber, simply dries out. This is how the leak appears. The reason may also be the use of aggressive chemicals by the car owner.

Problem with the cylinder block gasket. Such a defect is not associated with operational wear or the use of poor-quality lubricant. The problem lies either in the overheating of the motor, or in the power bolts not being tightened to the limit. Due to this, the gasket loses its properties and begins to leak. The defect in question should not be ignored, because it can cause water hammer or engine jamming. If there is a problem, the motorist must change the gasket.

There is a problem with the gasket in the oil filter. In most cases, this phenomenon can be encountered when using a low-quality filter, or due to an unscrupulous approach to the work of auto mechanics. Replacing the part or turning it until it fits tightly will help remove the defect.

Problem with oil seals. This defect most often affects the increase in engine oil consumption. The caps are located at the top of the power unit head. The temperature here is always high, and during overheating its value reaches a critical limit, which causes a leak.

5. Oil of inappropriate viscosity

Due to constantly tightening environmental requirements, automakers have to fight for every % to reduce mechanical losses by power units in order to achieve a reduction in fuel consumption. With regards to the cylinder-piston group, this manifested itself in the equipping of engines with thin rings that have little elasticity. Such actions helped reduce friction and increase part life, but required drivers to use only those types of oil that have a low viscosity.

The higher the value of the lubricant viscosity parameter, the stronger the oil film on the surface of the parts. When using high-viscosity fluid in power units equipped with thin piston rings, the latter simply cannot completely clean the lubricant from the walls. This becomes the cause of oil burn, which in symptoms is very similar to problems with wear of parts of the cylinder-piston group.

Most modern power units are designed to use synthetic oils. For this reason, the use of mineral lubricant in engine operation will lead to a decrease in lubrication performance, the formation of scuffing and the entry of a significant amount of oil residue into the combustion chamber. The same problems will arise when using high-quality lubricant, but not the appropriate viscosity.

Reasons for increased oil consumption in the absence of smoke

The main cause of this problem is visible oil leaks, which were discussed above. But what to do in a situation where a visual inspection did not bring results and no leaks were found? You shouldn't make hasty decisions. If the engine begins to consume significantly more oil, then there is a leak. It's just not so easy to notice.

The problem may lie in one of the following details:

Turbine. Such a structural unit of a vehicle not only needs constant lubrication, but it is also cooled by oil. If the shaft is heavily worn, oil may gradually leak onto the pump and turbine wheel. Along it it rushes into the intake, then into the combustion chamber, and at the last stage of its journey straight into the muffler. The result of this route appears in black smoke.
Distributor (ignition distributor). When the power unit is equipped with such a device, oil can easily leak through the O-ring. To determine the problem, you will need to remove the distributor cover and conduct a visual analysis of its components (if there is oil, it will be impossible not to notice it).
Defect on the camshaft plug. This part is installed on those engines with a pair of camshafts. Less commonly, it can be found on a single shaft, and then only if the motor does not have a distributor. If there is a defect, then oil will flow through the O-ring.

Timely maintenance and proper operation of the vehicle will guarantee low costs for engine repairs and the purchase of oil. The concept of “correct operation” means moderate operation of the motor. When you constantly give the engine high speeds during daily trips, then it won’t be long before the lubricant consumption increases.

Increased engine oil consumption: causes and solutions

A driver who does not regularly monitor the good condition of the various mechanisms of the car puts not only its normal operation in great danger, but also his life. But, perhaps, the main question of the proper functioning of a car is where does the oil go from the engine? We'll dive into why this is important and what could be causing this problem.

When to sound the alarm

There are no exact norms for oil consumption, as is the case with fuel. Older car models use more oil than modern internal combustion engines. If in the first case this indicator is critical - half a liter per 1000 km, then for modernized cars this norm can be 1 liter about 10 thousand km.

But, again, this is not the ultimate truth. There are other factors that we will consider below. But the main criterion is a sharp and constant drop in the oil level over several days.

But in order to “sound the alarm”, it is necessary to notice this problem. This is the main prevention of accidents. Auto mechanics advise checking the oil level before each trip. This is a truism. The level is checked on a cold engine (during movement, the oil warms up and increases in volume). And as a result, you will not get an accurate indicator.

At the same time, if you notice a decrease in the level, it is not enough to simply add lubricant; it is advisable to try to understand why the oil in the engine is leaking. In the article you will receive tips on how to make the correct “diagnosis”.

Oil consumption according to technical specifications

It is well known that any liquid tends to evaporate. Faster or slower, that's a different question. This process is accelerated at high temperatures, which are typical for engine operation. During normal engine operation, oil consumption should be minimal. At the same time, different brands and models of cars can consume different amounts of it. If you don’t have to constantly carry a can of oil and add it not every day, but once a week, there’s no need to worry.

Oil quality

Oil consumption largely depends on its viscosity and quality. If with viscosity everything is more or less clear, the thinner the oil, the more it flows through various seals, then with quality it is a little more complicated. The fact is that most car owners prefer to buy motor oil for their engine for “cheaper” reasons.

For example, open the filler neck on your engine's valve cover. What do you see inside? That's right, black soot. Where does the soot come from? Yes, from oil. If the temperature is too high, cheap motor oil breaks down and deposits on the walls. Oil loss occurs and its level in the engine crankcase decreases. This, in turn, among other negative consequences, leads to a decrease in the oil level in the engine, which again does not have the best effect on its ability to cool in the oil pan. This means that in the future there will be even greater overheating of the engine oil. Unfortunately, the durability of an engine with such (cheap) motor oil is expected to be very low.

So, the first disadvantage of bad oil is that it is destroyed by high temperature and actually ceases to be oil. The high-quality product that manufacturers recommend.

The second disadvantage of low-grade oils is that, when they break down, they pollute the engine with their decay products (carbon deposits). As a result, due to this carbon deposits, the piston rings barely move in their grooves, but must “play”, continuously tracking the, alas, no longer ideal, cylinder profile. The result is the occurrence (coking) of the piston rings. And, as follows from practice, the oil scraper rings will stop moving first. As a result, unremoved oil will remain on the cylinder walls, which will burn. A car with a gasoline engine will smoke bluish smoke. Diesel - no. All remaining oil in a diesel engine will burn without any smoke. The most curious thing is that if you measure the compression with this defect (the occurrence of oil scraper rings), the results will be excellent. The oil not removed from the cylinder walls will seal the gaps in the compression rings, and the pressure gauge will show the pressure even better than that of a new engine.

And the third thing that the use of low-grade oils will lead to is the destruction of all “rubber bands”. After overheating, the rubber of all oil seals, seals, and valve stem seals will lose its elasticity and turn into some kind of plastic. Naturally, after this an oil leak will appear. And all these problems arise from the desire to win something by servicing your iron friend by buying him cheaper oil.

Let's look at other reasons that cause a decrease in the oil level in the engine. The most common is a banal leak. Some problems can be fixed on your own, but others cannot be dealt with without a good specialist. First, let's look at what you can do yourself. If we talk about leaks, you should pay attention to the engine seals. Details below.

“Simple” reasons for oil consumption

It's easy to check. Remove the valve cover and take a look. If everything underneath is black, with thick deposits of fuel oil on all parts, then oil consumption is largely caused by oil waste. Second option. If, a week after changing the oil, it became black again (we are not talking about diesel engines, where the blackening of the engine oil does not mean anything), then one of two things: either the engine is terribly dirty and the new oil successfully dissolves this dirt in itself, or the new oil is rapidly destroyed and, naturally, decreases, becoming increasingly contaminated with the products of its waste. By the way, this is a very common reason for engine failure.

Oil may leak through the cylinder block gasket. This situation occurs if the power bolts are unevenly tightened during engine assembly. As a result, the gasket may become deformed and not ensure a tight fit of the parts. Clear evidence of this problem will be drips on the engine, which are easy to identify visually. Just look under the hood and the problem is obvious. In this case, it is important to take into account that low oil levels are part of the problem. Much more serious is the possibility in this case of antifreeze getting inside the cylinders. Here you can already “lose” the engine. Therefore, it is necessary not only to replace the gasket, but also to make sure that no coolant gets into the cylinders. There is doubt about the opposite - you need to change the oil completely.

Crankshaft oil seals are another “passage” for leaking oil. It is not difficult to determine a leak by looking at the seals. If an oil puddle has formed under the car while parked, then there is a high probability that the edges of the oil seals, intended for sealing, have become unusable (frayed, worn out). This is a fairly common problem because rubber itself is short-lived. One of the reasons may also be exposure to low-quality oil. Therefore, it is necessary to purchase only modern oil seals, adapted for operation in extreme conditions. Solving this problem is not difficult; it is enough to replace the worn oil seals with new ones and the question of where the oil goes from the engine will disappear on its own.

Oil may escape through the oil filter gaskets. This unpleasant situation occurs as a result of hasty or inept filter replacement. To make it more clear: the filter was either not tightened, which eliminates the tightness, or the gasket was wrinkled and the result is the same. In the first case, you need to tighten the filter more tightly. In the second - see if the gasket is in good condition, if not, replace it, but be sure to lubricate it with machine oil. This guarantees its elasticity, on the one hand, and uniformity of fit, on the other.

Oil seals (they are oil seals, they are also valve seals). These parts are located at the top of the cylinder head. And as a result, they are exposed to particularly high temperatures. Considering that they are made of rubber (even if it is highly durable and heat-resistant), it is rubber and will not be able to withstand critical temperatures for long. The properties of the caps begin to resemble plastic more and do not perform their functions. As a result, the oil begins to leak out, covering the exhaust valves with organic deposits. Another leak option is a defective cap, the effect is the same. In this case, only replacing the caps will help. For those who like fast starts, a special warning - constant extreme driving can “rip” it from its place (if it was not installed correctly).

“Complex” reasons for oil consumption

A much more unpleasant and difficult to eliminate cause of low oil level is coking of the piston rings. Piston rings perform their functions well only when clean. Thanks to this they have excellent mobility. If they coke and sink, there can be no question of any compaction. In this case, a decrease in compression of one or more cylinders is noticed. It is impossible not to notice this from the engine's operation. There are several reasons for this phenomenon: low-quality and “old” oil. In this case, you can try to do without major repairs. There are special products (chemicals that can dissolve plaque) that need to be used to treat the rings. And of course, a complete oil change will be required.

High cylinder wear has a greater impact on oil consumption than the previously discussed piston ring problems. Boring can solve the problem in some cases. But there are also “hidden” integrity violations up to a certain point - these are microcracks, small chips. They are figuratively “filled” with oil and this leads to a slight, but daily decrease in the level, which becomes clearly noticeable after a week and even more so a month.

Another rather specific problem associated with the design features of cylinders is their deformation. When installing anchor studs, peculiar distortions occur that affect the installation and operation of the O-rings. In fact, the latter cannot provide a sufficiently tight fit due to the “crescent-shaped gaps”. Using relatively soft rings can help out. But again, you will “eat” more oil.

Oil scraper piston rings. These engine elements are designed to ensure that the required amount of oil reaches the compression rings. And as a result, they do not have constant lubrication, that is, they do not “bathe” in oil, like some parts. In this case, friction increases and wear occurs faster. There is no metal that can last forever. This also applies to these car parts. High oil consumption indicates that the piston rings have worn down significantly. Do not try to solve this problem yourself. Here, without a service station, you can only “break wood.”

Oil can also escape through the piston rings. This problem occurs as a result of overheating. There are critical temperatures at which piston rings retain their elasticity well and perfectly perform their functions. This range is defined as 180 to 200 degrees. A small “plus” is allowed, since all parts are created with an additional margin of safety. But at the same time, even a one-time significant increase in the operating temperature of the engine can lead to a decrease in the functions of the piston rings, and as a result, an increase in oil consumption. A good motor mechanic, service station, car service will help. In general, you should not self-medicate.

Intervalve jumpers. This is one of the so-called thermal fatigue defects. In this case, in addition to the wear of the pistons, the combustion chamber is damaged; it loses the necessary seal. As in the previous case, contact only specialists.

Specific reasons?

We would like to note several points not related to the design features of the car. And more importantly, you can influence them without having the knowledge of a car mechanic.

Extreme riding. Fans of fast starts, sharp braking, driving at the limit of the car in general and the engine in particular should be aware that this cannot but affect the engine. The pistons work under heavy loads, the temperature rises, you can remember and review the previous subheadings and descriptions of the problems associated with this. Therefore, there are two options for solving this issue. Travel in normal mode, provided for by the operating characteristics of the machine. Or an additional can of oil in the trunk and a certain amount of money for repairs.

Late combustion causes increased oil consumption. This is due to the fact that the engine temperature rises with all the ensuing consequences. In this case, it is necessary to adjust the ignition and use high-quality fuel with an octane rating that matches the model of your car.

Turbocharger lubrication. These are, in principle, natural losses that are difficult to influence. But as a rule, such consumption is associated with expensive foreign cars with a turbo engine.

Poor quality oil. The higher the viscosity, the better the lubricant. Everything seems to be clear with this. But at the same time it creates additional waste in the pistons. And this is where the fork comes in: to increase engine life or oil consumption. It is an indisputable fact that it is necessary to buy licensed oil from well-known manufacturers and at least somehow protect yourself.

Is there an oil consumption rate? There is no exact figure as such. But if a month ago you did not have such a problem, and now it is becoming quite obvious, then the problem is not in the design features of the car.

At the same time, a sufficient amount of oil will avoid serious engine damage. We have looked at the reasons that allow you to understand where the oil goes from the engine, this will help you monitor proper operation and avoid serious expenses for repair work.

Causes of high engine oil consumption that need to be addressed urgently

Increased consumption of lubricants can seriously alarm the owner. Well, did the cylinder coating “tear up”? We hasten to reassure you that there can be many reasons for oil consumption and not all of them are costly.

Some of the horror movie scenarios “where does the butter go” are not at all fatal and end with a happy ending. Others are actually fatal and are clear signs of the need for repair or, if this is not possible, replacement of the engine.

Incorrect oil

Let's start with easily removable reasons. One of them is not quite suitable oil, the use of which causes increased waste. There is a similar example in our personal practice: a middle-aged Volvo with a working “turbo-five” (even compression in all cylinders, a turbocharger in good health, no leaks through the seals) spent clearly above the norm and, as they say, out of the blue - with a calm driving style.

Shutterstock/VOSTOCK Photo

What was surprising was that its parameters corresponded to the manufacturer’s recommendations. Switching to oil with increased high-temperature viscosity completely solved the problem. As an experiment, the choice fell on the products of another, more well-known and well-established brand. However, we will not exclude the possibility of a decrease in oil waste on products of the same brand, but with a higher viscosity.

Valve stem seals

Another reason for oil “burning”, which has a relatively easy solution, may be hidden in worn valve stem seals, which are located on the valves and prevent oil from entering the combustion chamber.

Over time, the seals “tann”, that is, they lose elasticity and begin to leak lubricant. There is nothing wrong with replacement - the caps are essentially consumables.

Leaking through seals and gaskets

Over time, oil can begin to leak through the seals, for example, leaving the engine by finding loopholes in the front crankshaft seal. This can happen for a variety of reasons. For example, with a high mileage of the car, when the internal part of the oil seal wears out due to vibrations of the crankshaft, long-term downtime of the car and, as a result, a dry or “hardened” part, or its poor quality or improper installation.

A leaking oil seal can damage the timing belt and must be replaced. The rear seal of the crankshaft or camshafts may leak, or it may ooze from under the valve cover or engine pan gasket. It should be remembered that dust and dirt are guaranteed to accumulate at the leak site, making its source noticeable, or after parking you will see oil drops or even a puddle on the asphalt after parking.

Crankcase ventilation system

One of the common reasons not only for oil burnout, but also for all sorts of unpleasant problems is a contaminated crankcase ventilation system. There is an explosive mixture in the engine sump - vapors of unburned fuel, gases, water particles and oil mist. All this has the most negative effect on the condition of lubricants. A crankcase ventilation system that removes excess gunk not only extends oil life, but also reduces crankcase pressure that can force oil out and reduces emissions.

If it ceases to perform its functions, then the increasing pressure in the crankcase can squeeze out the oil dipstick with quite predictable consequences. Surprises come from a stuck or clogged valve, which regulates the pressure of gases entering the intake and provokes an oily appetite.

Turbocharger oil consumption

The boost system is a thing! Modern installations, as is common nowadays, make the nature of the unit flexible - the “shelf” torque is achieved in a fairly wide speed range, which is convenient for driving. But at the same time, the complex design operates in extremely extreme temperature conditions, places its own demands on the oil, and itself can consume it due to design features and in the event of malfunctions. The bearings are lubricated by engine oil, which means they are very sensitive to a drop in its level. When the volume of lubricant decreases, the turbocharger bearings begin to run dry and the boost runs the risk of failure.

Significant oil consumption can be observed when the “snail” malfunctions, namely, when the shafts and bushings, which are fitted very tightly to each other, so as not to leak lubricant, are worn out. But as the gap increases, the oil will flow through the “cold” compressor part of the turbine to the inlet. The reason for the excessive appetite may be increased vacuum at the inlet, which will suck oil from the turbine.

Oil getting into the cooling system

Above we have listed some unpleasant, although not fatal, reasons for increased consumption of lubricants. The main thing is not to start. And now the scenarios are more serious and dramatic. For example, oil getting into the cooling system. Spots on the surface of the antifreeze in the expansion tank should be seriously alarming: coolant and oil are in different systems and mixing means a leak, which with a high probability can mean further engine failure.

Why did this happen? Probably due to a blown head gasket, damaged cylinder head, faulty cooling system pump or, say, oil cooler.

Piston ring wear

Rocker smoke from the exhaust system under load often hints at critical wear of the rings in the engine - they can no longer remove oil from the cylinder walls, and it breaks into the combustion chamber, where it is burned along with the fuel-air mixture.

Other symptoms include decreased power, increased fuel consumption, and blackened spark plugs. In this case - only repairs.

Seizures on cylinder walls

For dessert, let’s touch on a topic that is the worst nightmare of not only adherents of the Porsche Cayenne and Mercedes-Benz S600 Biturbo, but also other motorists, for example, owners of Hyundai and Kia with a supercharged G4KD gasoline engine. The surface of the cylinders with scoring grooves is guaranteed to mean high oil consumption and “getting” into major and costly repairs with liner replacement or even replacement of the cylinder block.

The trigger for the appearance of scuffing is the absence of an oil film on the cylinder walls and metal-to-metal friction. Another question is why this happens. The reasons may be different, for example, oil starvation, reduced oil pressure, “sporty” driving style, low-quality oil or oil that does not meet its characteristics, or has lost its properties.

Motor oils and everything you need to know about motor oils

How to determine engine oil consumption

Oil is an important component of the engine system and ensures stable operation of the vehicle. It covers parts and working elements with a protective film, helps to avoid unwanted friction of parts, which in turn prolongs the performance of the engine.

How to determine engine oil consumption, reasons for excess consumption

Any vehicle has a very useful mechanism called an oil meter. The dipstick is necessary to check the oil level. Any engine needs lubricant. In the opposite situation, the motor will not work for long. Thanks to the oil meter, you can easily find out the answer to a common question: what is the acceptable amount of oil product consumption? Quite often, a car begins to consume an excessive amount of oil, and this, in turn, may imply a quick overhaul.

Motor oil - consumption rates

When operating properly, engines consume about 0.2 liters of lubricant per 1000 km. ways. However, several factors may influence the amount of oil used:

Increased oil level in the system. This indicator leads to increased costs of the oil component, due to the exclusion of excess through the crankcase ventilation system.
Engine oil viscosity. The liquid phase of the lubricant burns faster than the thick phase. For example, the seasonal type of oil becomes liquid very quickly when heated, and, therefore, it is consumed faster. As for all-season motor oil, it is thick and has noticeably lower consumption during operation. This is especially noticeable on long trips.
Driver's driving style. With increased loads during engine operation, oil consumption increases, including during engine break-in.
System leakage.
Engine defect, including factory defect.

All-season oil that remains in the engine for a long time loses viscosity over time. It needs constant topping up.

Aspects of acceptable and excessive oil consumption

The normal consumption of the oil component of a newly purchased car is considered to be 0.1-0.3 percent of the fuel consumption. For large cars, the rate of “eating” is at the level of 2-3 percent. As a rule, this information is contained in the transport passport. But constant monitoring of the amount of oil consumption is required.

There is an opinion among car owners that oil should not be topped up between changes. This means that it will change every 10 thousand km. A little mathematical calculations, and it turns out that for 1 thousand km. along the way, vehicles will need approximately one hundred grams of oil. Let's consider the main factors for increased consumption of oil products:

Burnout of motor oil on cylindrical planes.
Wear of parts of the machine's power unit. In this condition, the engine requires a significant amount of engine oil.
An internal combustion engine with a turbine has increased consumption rates, since an additional amount of the component is spent on the turbocharger, or more precisely, on its lubrication.
Violation of the working condition of the seals.

The most common case of excessive car oil consumption is a leak. There are many reasons for leaks; to find out the true cause, it is enough to take the car for inspection to a service station. There they will carry out work on the tightness of worn-out mechanisms in the system.

A very common leak point is the camshaft and crankshaft seals. It is worth remembering that this type of leak is very insidious, since the problem can only be corrected with the help of a special tool. The problem is easy to detect - the appearance of an oil stain on the surface of the crankcase walls. It should be corrected as quickly as possible, since this situation does not bode well for a good outcome.

But the most serious problem is considered to be an engine oil leak in the oil pan. To detect this defect, the protection should be removed, but the car must be on a special lift. Every time you fill up the oil, you need to check the condition of the pan. The most common variation of a leak is considered to be a non-working condition of the crankshaft seal.

Additional reasons for excess oil consumption

An indicator of increased oil consumption can be smoke from the exhaust pipe. If the exhaust is visually gray-blue, then the car burns oil excessively during operation. But if black smoke is visible to the naked eye, this may indicate a malfunction of the injection system.

However, burnout of the lubricant is a secondary consequence, and the main reason lies elsewhere. To understand this issue, you should completely disassemble the motor. Upon examination, a professional can identify the initial cause of increased oil combustion - the need to replace oil seals, wear of rings or mechanism parts, or product mismatch for the machine model.

There are quite frequent cases when excess oil consumption occurs due to significant engine contamination or increased pressure of gaseous substances. Normal oil consumption depends on the vehicle and the type of engine. For example, a small car consumes a liter of lubricant per 1 thousand kilometers. This figure is very high for this class of car, but for V-shaped engines the consumption is considered optimal.

The best option for choosing oil for a car

Having decided on the timing of replacement and lubrication of system parts, the next question arises - what kind of oil to fill in? To solve this problem, you must carefully study the technical service book of the vehicle or the operating manual. The certificates provide a detailed list of oils, thanks to which the engine can become long-lived - documentation of this type contains permissible values for use.

It is worth noting the fact that manufacturers will offer certain brands of motor oil because it is of commercial interest to them. The best option when choosing engine oil is to take into account the parameters and physical data of the car: production date, power and volume of the internal combustion engine.

The next parameter of acceptable values is viscosity, which, as a rule, is indicated on the labeling of any package of oil for automobile engines. In practice, the symbol for this indicator is 10W50 or 0W20. The first number indicates the viscosity of the oil solution when the engine is cold, and the next number, after the letter designation, indicates the performance characteristic, in accordance with the classification of the Society of Automotive Engineers (SAE).

The English letter “W”, when marked twice, denotes all-season oil. But if there is no number after the letter “W”, then this means a winter variety. If the letter designation itself is not there, it’s a summer option.