Why did an emulsion appear in the engine? White bloom

In the process of surface diagnostics, you should start by checking the level in the cooling system. To do this, you need to unscrew the expansion tank cap on a slightly cooled or cold unit. A decrease in the coolant level for no apparent reason may indicate a malfunction in the area of the block head, problems with the cylinder head gasket or the cylinder block itself.

Destruction or defects in the gasket are the most common reason ingress of moisture into the oil. In other words, the oil contains a coolant, which is a mixture of a chemical concentrate and water.

The tightness of the gasket is usually violated as a result of natural wear and tear of this element, and after overheating of the motor. In the event that overheating has previously taken place and the gasket has not changed, then the condition of the oil must be monitored separately.

Natural wear of the gasket occurs due to the fact that the element experiences significant temperature loads, constantly works under conditions high blood pressure... As a rule, the gasket fails on runs from 100 thousand km. and more. With a punctured gasket, the engine runs unevenly, antifreeze is leaving.

To eliminate a malfunction that arose after natural wear and tear, you just need to remove the cylinder head and replace the gasket. If the motor has overheated, then it may require.

After overheating, the cylinder head of the engine often "leads". This means that the geometry is violated, the mating planes of the BC and the cylinder head do not match, and it is not possible to achieve a normal fit even after replacing the gasket. In such a situation, the engine requires more serious repairs or even replacement of the cylinder head.

Exhaust gases in case of problems with the gasket can enter the cooling system, as a result of which, after unscrewing the radiator cap or expansion tank, you can see smoke and coolant bubbling of varying degrees of intensity.

The appearance of cracks in the cylinder block or the head of the block can also occur as a result of overheating or temperature extremes, as well as be the result of wear, damage, or.

In the latter case, a common reason is the use of running or distilled water instead of antifreeze, filling with low quality coolant, a large amount of water in relation to the concentrate, or an incorrectly diluted antifreeze or antifreeze concentrate with water.

We also note that cracks or deformation of the cylinder head can occur if in very coldy immediately turn off the engine, which previously worked at the limit. For example, such consequences are sometimes caused by an abrupt stop of a heated unit after driving along the highway on maximum speed... Even microcracks in the block and head can also be the result of accidents, aggressive vehicle operation, driving over serious obstacles, etc.

The possibility of active accumulation of condensate in the inner cavity of the engine crankcase should not be ruled out. This happens when weather or other conditions contribute to significant temperature fluctuations. During such changes, outside air enters the crankcase through the breather and the crankcase ventilation system.

In some cases, moisture from the air in large quantities can condense on the walls, after which it enters the oil and an emulsion forms on the dipstick and lid. A conventional oil change helps to solve the problem, before which it is recommended to additionally flush the engine with special flushing compounds.

Heavy wear of the CPG, combined with the ingress of antifreeze into the cylinders, can also cause the formation of an emulsion. In this case, the coolant not only enters the cylinders, but also flows through piston rings into the crankcase.

As a result, the oil dilutes, the coolant level drops, and the oil level rises. At the same time, the emulsion and the loss of its protective and other properties by the oil are clearly visible.

We add that if the CPG is in order, then the antifreeze will not get into the crankcase. In this case, a strong accumulation of coolant often leads to a water hammer. It is also a common situation when, with minor leaks, the engine starts, but after starting it is strong.

What is the bottom line

As you can see, the main cause of emulsion on the dipstick and oil filler cap is working fluid cooling systems. In such a situation, it is recommended to stop operating the internal combustion engine and immediately carry out repairs.

To determine microcracks and other subtle damages, check the cylinder head or BC for leaks in a special bath. This method involves the supply of air under pressure and allows you to detect even the smallest defects.

After diagnostics, you can accurately verify the severity of the problem, as well as the possibility or impossibility. In any case, prior to the inspection, you should not make a hasty decision about the need to replace damaged elements.

Finally, we add that if in the cold season a white emulsion is visible on the oil filler cap for no other reason, while the amount of emulsion is very small and antifreeze does not go away, then for a start it will be enough to simply change the engine oil.

It may also be necessary to slightly reduce the subsequent service interval. With the onset of heat, the problem may disappear by itself, since the car will not be subject to significant temperature changes, and excess moisture will be removed from the engine along with changing the lubricant.

Why does an emulsion appear in oil: causes and consequences

The emulsion looks like fine foam white, is formed when water or other liquid enters the engine oil, followed by active stirring. In some cases, such a plaque does not pose a danger and you should not worry about its presence. But this is not always the case, an emulsion in the engine oil can also indicate the appearance of serious problems with the power plant and the need for repairs.

The presence of water in oil is generally considered unacceptable as it affects performance and. But the design of any engine includes a breather that maintains a given pressure in the crankcase. In essence, it connects inner space power plant with atmosphere. Therefore, through it, air enters the cylinder block from the environment, in which moisture is necessarily present - water particles.

V summer period the temperature difference is low, so most of the water remains in a gaseous state and is then removed along with the blow-by gases. In winter, the temperature difference is significant, so moisture condenses into a liquid, settles on the internal surfaces of the engine, where it is added to the engine oil. This is where the white emulsion is taken on the oil filler cap.

Therefore, the presence of a small whitish coating on this filler cap or oil dipstick in winter period is the norm, and there is nothing wrong with it.

Video: Emulsion under the valve cover !!!

But the appearance of a yellow emulsion on the oil filler cap in the summer, or its amount is significant, indicates problems with the engine. The same applies to traces of emulsion on the engine oil dipstick. In a serviceable engine, foam does not appear on it even in winter, and if it is detected, malfunctions have appeared in the engine.

Additional symptoms of malfunction

As noted, an emulsion is a mixed mixture of water and oil in the form of a foam. An abundant amount of white or yellowish foam on the cover and dipstick signals that liquid is leaking into the engine crankcase, and it is only present in. Therefore, the place of leakage should be primarily looked for in those parts of the engine where the lubrication and cooling channels run side by side.

Note that the appearance of a coolant (coolant) leakage inside the engine may be accompanied by a number of other signs:

Constant decrease in coolant level in expansion tank and the need for periodic topping up.
Oil film in the expansion tank.
The engine oil level is too high.
Abundant White smoke from the exhaust pipe.
Interruptions in engine operation.

All this indicates the ingress of antifreeze into oil channels... If you do not take any action and continue to operate the car, then the engine will be damaged due to the lack of normal lubrication, and an expensive overhaul, or a complete replacement of the motor.

Where to look for the cause of antifreeze leakage?

Leakage can occur due to:

block heads;
cylinder head gaskets;
cracks in the cylinder;
cracks in the block head.

Let's start with the block head. This component of the engine is made of non-ferrous metals and, when installed, is strongly bolted to the cylinder block.

As a result of expansion of the metal due to overheating, the head warps. In some places, gaps appear between the cylinder head and the block, through which technical fluids enter the channels of other systems. That is, the coolant simply reaches the oil channels through the slots and is mixed with the lubricant.

This malfunction is not very difficult and quite amenable to repair. But this will require dismantling the head, grinding its surface adjacent to the block, replacing the gasket and lubricant. When changing, it is imperative to flush the engine and the lubrication system with the replacement of the "old" oil with antifreeze impurities.

But the warpage of the block head does not often cause the formation of an emulsion. A more common problem is cylinder head gasket failure.

This happens for the same reason -. But if the head warps only with prolonged exposure to high temperatures, then a short-term overheating is enough to damage the gasket. And since the lubrication and cooling channels pass through the gasket, the bridges between them are destroyed by high temperature. Note that breakdown does not always occur only between channels. Damage can also connect the channels to the cylinder or lead to the outside of the engine.

Although the breakdown of the cylinder head gasket is the most common reason for the appearance of a white emulsion in engine oil, it is also considered the easiest to eliminate. To do this, you just need to replace the damaged gasket with a new one, as well as replace the engine oil and flush the engine. An experienced car enthusiast is able to carry out repairs within 4-5 hours.

Although cracks in the cylinder rarely happen, it can also become the cause of the formation of an emulsion. This usually occurs due to defects in the metal structure of the sleeve.

Video: Emulsion on the oil filler cap

The existing defects over time can lead to the appearance of a crack in the cylinder wall, and as it cools, the liquid begins to seep into the combustion chambers. Most of the fluid exits the engine through exhaust pipe, but a little of it gets into the sub-piston space, hence the emulsion is taken.

It is possible to repair an engine with such a breakdown only if the liners in it are removable and can be replaced. But in a number power plants the cylinders cannot be dismantled, in which case the entire block must be replaced.

Another serious problem, the consequence of which is the formation of an emulsion in the engine oil, are cracks in the head and block. They can form from overheating, internal metal defect, shock loads.

It is very difficult to identify such damage, especially in the block, since the lubrication and cooling channels pass inside it, and it is not always possible to inspect or diagnose them.

It will also not be possible to repair such damage. That's why component the engine with a crack is simply replaced.

In order not to make unscheduled engine repairs due to the appearance of an emulsion of engine oil, it is enough only to carry out Maintenance, especially regarding the replacement technical fluids, and also to prevent overheating of the motor. And for this, you should constantly monitor the temperature regime while driving.

If a problem with the emulsion in the engine oil appears, it is better to start the search with the simplest thing - cylinder head gaskets. In this case, after dismantling the head during replacement, it should be checked for warpage. It is very easy to do this even in garage conditions... To do this, place the head with the surface adjacent to the block on clean glass. Irregularities formed as a result of warping will be clearly visible.

Usually the reason lies in the head and its gasket. Cracks in the liners, block and cylinder head are very rare.

Car service specialists and automakers recommend changing the oil in gasoline or diesel engines every 10,000 kilometers. But even if this regulation is observed, sooner or later the car owner notices that an emulsion has formed on the oil filler cap. In appearance, this emulsion resembles mayonnaise and plunges many drivers, and especially beginners, into shock. By the way, the color of the "mayonnaise" may vary. Let's look at the reasons for this phenomenon, and also find out how to deal with the problem.

What is a white emulsion?

Modern engine oils that are sold everywhere today are hydrocarbon-based. When gasoline is burned, various substances are formed. These are antifreeze, water, alcohols, acids, and also peroxides. All these substances in hydrocarbons are mixed, as a result of which a white emulsion forms on the oil filler cap. Why does it appear here? It's simple - because of the huge number of microscopic bubbles, the emulsion turns white in case of severe oil contamination. The filler cap and dipstick are one of the coldest places.

Therefore, "mayonnaise" adheres well to these surfaces.

Causes

Car service specialists and simply experienced car enthusiasts state that the reasons for the appearance of the emulsion are huge. Most often, this white mixture can occur when in the crankcase power unit coolant enters. This can happen due to the breakdown of the gasket between the cylinder head and the engine block. Also, the emulsion on the oil filler cap may indicate cracks in the cylinder block or in the head. Another possible reason for the ingress of antifreeze into the crankcase is the deformation of the cylinder head elements. Condensation is still possible, especially in winter.

Also, "mayonnaise" is formed when there is no ventilation of crankcase gases in the engine. The gas is hot and contains a large amount of water, which is deposited in the form of condensation at the top of the motor. As a result, a white emulsion builds up on the oil filler cap. It is rather difficult to find out the exact reason why this frightening “mayonnaise” arises for many motorists. But in most cases this is due to the breakdown of the cylinder head gasket. As a result, the coolant flows freely into the oil passages and mixes with the oil there. It should be noted that if antifreeze gets into the grease, it can no longer be used. Both oil and coolant must be replaced. This is true for all car models without exception. An emulsion appears on the oil filler cap on all machines, without exception, if there is damage or the operating conditions are violated. Often motorists are faced with "mayonnaise" different colors at the first drops in temperature - in autumn and winter. But don't sound the alarm. This is condensation due to the temperature difference between a warm engine and the outside air. When the engine is warmed up, then the moisture in the oil will evaporate, but some of it will accumulate in the form of condensation on the filler cap. What is interesting: many cars are susceptible to this disease, but the Gazelle practically does not suffer from this.

Possible consequences

When in lubricating products water, condensate or coolant enters, the oil quickly loses its properties. Accordingly, the lubricating properties are reduced. In winter, oils can even crystallize, which will not affect the engine in the best way. The film between the rubbing pairs of parts leads to rapid wear of all, without exception, parts in the motor.

Most often, in these cases, the engine just goes crazy, and this is an expensive repair. Therefore, if an emulsion has formed on the oil filler cap, the reasons should be carefully investigated. It is urgent to find the malfunction and fix it.

About condensate more

Even those who store their cars in the garage face this problem. But most often it worries those who park their cars in the yard. If the car regularly spends the night on the street in the fall during the rainy season, then a large amount of water vapor may well enter the crankcase. They condense in tubes and on oily surfaces. From 1-2 g of condensate can get into the motor at a time. This is sufficient for an emulsion to form on the oil filler cap. By the way, bubbles will be visible on the dipstick as well. V winter time the owner will see mayonnaise very often. If the car is constantly driven for short distances, and the engine does not warm up to 90 degrees, then this is also one of the reasons why condensation accumulates in the engine. "Treatment" is carried out by long runs, or by warming up to operating temperatures.

Faulty crankcase ventilation system

If the ventilation system is clogged and does not work as it should, then gases and vapors will try to escape through the probe and other places in the internal combustion engine. In this case, it is not surprising that an emulsion appeared on the oil filler cap.

The only good news is that the oil is clean and there is no antifreeze in it. If you fix the crankcase ventilation system, then you don't even have to replace the lubricants.

Coolant: a serious case

We need to consider this topic in more detail. One of the most common sources of liquids that form an emulsion when mixed with oil is antifreeze, or antifreeze. Why does this happen and how does the coolant get into the motor? It's simple. The coolant will get through damage in the area of the cylinder head gasket from the cooling circuits. Antifreeze seeps there under high pressure. This is normal because there is much less oil in half the amount of oil.

Diagnostics

To check these reasons, the lubricant is drained from a sufficiently warm engine into a previously prepared container. In hot oil, even with the naked eye, traces of coolant will be visible, which will turn into an emulsion as it cools. If there is a lot of water in the antifreeze, then most of it will accumulate under a layer at the bottom of the crankcase. Naturally, this slurry will be sucked in by the oil receiver. If a yellow emulsion has formed on the oil filler cap, then it is better to temporarily stop operating the vehicle. A viscous mixture will clog the lubricant passages. Connecting rod bearings, piston rings, main bearings with such a liquid will quickly fail.

Poor fuel as one of the reasons

If the oil contains an emulsion, this is a consequence of the fact that the car was filled with low-quality gasoline.

Today, kerosene, alcohol, water and other ingredients are sometimes contained in the fuel. Conclusion - in order to exclude the formation of "mayonnaise" in the engine, it is better to refuel at proven gas stations.

Breakdown of the cylinder head gasket

If an emulsion is visible on the oil filler cap, the cause is often a leak in the gasket. Breakdown is possible due to burnout due to overheating or as a result of physical obsolescence and wear of the gasket. But such cases only occur on older engines that have not been monitored. The main sign of a breakdown is unstable work motor. Also, the coolant will be noticeable from the expansion tank. If you carry out the diagnostics in a timely manner, then you can limit yourself only to replacing the gasket. This is done in literally two hours. If you let go of the situation, then everything will be much worse.

Cracks in the cylinder head and block

An emulsion on the oil filler cap (including VAZ-2107) is often formed due to cracks in the head or block. This happens due to the freezing of the antifreeze. It is necessary to monitor the characteristics of the working temperatures of the coolant. Do not pour water into the radiator.

It remains inside the system even if the coolant is completely drained. As a result, water freezes in the most inappropriate places. Most often, the channels of the block or the cylinder head crack. Also, the engine is deformed due to mechanical shock. If there was a frontal impact on the car, you should not exclude the possibility of cracks on the block.

Water in the engine sump

This problem can only be fixed by complete replacement lubricating fluid... It is best to flush the engine with a specialized flush. An emulsion often forms on the oil filler cap in winter due to temperature changes.

The situation when water enters the crankcase through the combustion chambers is very rare in itself. This is possible only on engines where the piston group is in poor condition with "tired" rings.

Conclusion

As you can see, "mayonnaise" is bad sign for the motor. It is important to constantly monitor the condition of the power unit. If you do not fix the problem in time, you can get expensive repairs. At the first sign, when an emulsion forms on the oil filler cap (whether it is condensate or not, it does not matter), you must immediately take the necessary measures.

The good condition of the car can be judged by many signs, sometimes indirect, sometimes clearly indicating the occurrence of a particular defect. The driver should be attentive to everything unusual that happens to his car. So, for example, when checking the lubricant level in the engine before driving, you find a white emulsion on the dipstick (foam). And what is it fraught with for the car?

There is a white emulsion on the dipstick - what are the reasons?

It should be noted right away that this may already be a sign of a malfunction. Typically, a white emulsion found when checking the lubricant level appears when coolant enters the crankcase. This can happen, for example, due to:

Breakdown of the gasket between the cylinder head and the block itself;
- the appearance of a crack in the cylinder head or block;
- cylinder head deformation;
- water ingress into the engine cylinders, and then into the crankcase;
- the formation of condensation in the crankcase.

Sometimes it can be difficult to determine what causes a white emulsion to appear on the dipstick when checking the lubricant level. However, the consequences will be quite unpleasant. The properties of the oil deteriorate, which complicates the operation of the engine and leads to possible seizure.

More often, foam on the dipstick appears after coolant enters the lubrication system. This should be confirmed by monitoring the level of these two fluids. If, according to the marks during the check, the level of the latter in the crankcase increased, and the antifreeze in the tank, on the contrary, became less, then you can assume that the emulsion appeared for the above reason. It is necessary to look for a place where the coolant penetrates, and after eliminating the malfunction, also change the oil. Until the causes are eliminated, it is better not to use the machine and do not start the engine.

What else can you say about this?

Operating conditions can also be the reason for this phenomenon. Very often, foam appears on the probe in winter or during a cold snap. This is due to the fact that condensation forms when the heated machine cools. When the engine is hot, moisture vapor entering the oil evaporates and then condenses on the cover, for example, as shown in the photo.

Often, such condensate, in addition to the lid, also appears on the dipstick. Another reason for the formation of such muck can be bad oil... When using a good, not "burned" product, this does not happen.

The consolation is that this appears only in winter and disappears with warming. Usually, this phenomenon does not pose a direct danger to the motor; it does not require emergency measures. However, it is necessary to carefully monitor the levels of lubricant and antifreeze, it is quite possible that what is happening is only a harbinger of breakdown of the cylinder head gasket.

Summing up

A rather unpleasant thing is the appearance of white foam on the probe. Most often this is the result of coolant entering the engine lubrication system due to a breakdown of the gasket between the cylinder head and the block itself.

As a result, as a rule, it, as well as the oil, needs to be changed. If its level has not increased, there is very little foam, and the antifreeze has not become less, and in addition, an emulsion has appeared on the cap of the oil filler neck, it is quite possible that the reason for this was poor quality oil or condensation of moisture trapped in it. In general, when this problem appears, it is possible to operate the machine, but here everyone decides for himself what to do.

But if you close your eyes and pretend that nothing is happening, then after a while, you may have to do a major overhaul of the engine.

Greetings to you friends on the do-it-yourself auto repair site. Checking the oil in the engine is one of the main tasks of the car enthusiast. With its help, you can not only find out the level of the lubricating fluid, but also assess the condition of the oil.

Emulsion on the dipstick

For example, darkening and the appearance of dark impurities in it literally "screams" about the need for replacement, and the appearance of small metal shavings is a sign of increased friction between engine elements ( possible reason- incorrectly selected type of oil).

But what is most misleading is the white emulsion on the dipstick. What is the reason? Does the engine need to be repaired? Should you panic at all?

The main reasons for the appearance of emulsion on the dipstick

Remember that any foreign matter, discoloration, or emulsion on the dipstick is a sign of malfunction. The only question is how serious the problem is. In the case of white "foam", there may be several reasons:

Distortion of the cylinder head surface;
the appearance of a crack (defect) in the cylinder block or on the head itself;
breakdown (burnout) of the gasket located between the power unit block and the cylinder head;
ingress of moisture into the combustion chamber of the engine. After that, water can enter the crankcase;
the formation of condensation directly in the crankcase due to sudden temperature changes.

The first three malfunctions are interconnected, because in all cases the result is the same - the coolant enters the engine and mixes with the oil.

In such a situation, make a few more checks:

Inspect the perimeter of the engine along the joint of the cylinder head and cylinder block. The presence of oil leaks is a clear sign of damage to the gasket or, even worse, of the engine metal itself;
appreciate the color of the exhaust smoke. If it is thick and white, then the probability of the problem we mentioned (mixing oil and antifreeze) is very high;
look into the coolant reservoir. If there is less antifreeze or antifreeze, and the oil level, on the contrary, has increased, then everything is clear without words.

Another problem is condensation. It would seem where to come from. But with special conditions operation, it may well appear in the engine. As a rule, foam occurs during the cold season.

Let's imagine a situation. The car is well warmed up and "spends the night" on the street. A sharp drop in temperature leads to the formation of condensation. Moisture enters the oil, evaporates during operation and may appear on the cover or on the dipstick. With the advent of heat, this problem usually disappears.

A few more versions cannot be discarded - low quality oils, choosing the wrong brand or mixing formulations different types, for example, "synthetics" and "mineral water". The latter rarely happens, but through negligence it happens.

What happens if a white emulsion appears on the dipstick?

In such a situation, you need to remove the cylinder head and change the gasket (grind the edges of the block or head). If you do not take any steps, then the consequences are unlikely to please you:

The appearance of foam worsens performance characteristics oils;
the quality of lubrication of the main elements of the unit decreases, the likelihood of overheating and the failure of the power unit increases. The worst result is engine jamming, after which you will have to spend more than a dozen thousand on overhaul.

If the reason is the poor quality of the oil, then it is worth draining the old lubricating composition, rinsing the engine well and pouring in a quality product. In the case when the cause of the foam is the appearance of condensation, then with the arrival of heat, the problem will disappear by itself.

Be attentive to your car, check the oil level and assess the condition of the lubricant. If on oil dipstick white emulsion, don't panic. Just diagnose, taking into account the recommendations in the article and draw the right conclusions.

If a malfunction is identified in time, then it is much easier to fix it. Have a good road and, of course, no breakdowns.