Emulsion on the oil filler cap causes. Why does emulsion appear in the engine?

24.09.2019

Experts recommend changing the oil every 8 and 10 thousand kilometers on diesel and gasoline engines respectively. However, when you open the cap, an emulsion appears on the oil filler cap. This “mayonnaise” definitely shocks drivers. What should you do if an emulsion has formed on the oil filler cap of a BMW or other car? Let's consider.

Causes

The presence of so-called mayonnaise can say a lot. Often this emulsion occurs when coolant enters the crankcase system. It happens:

Due to a breakdown of the gasket between the block and the head.
There is a crack in the head or block.
Deformation of the cylinder head element.
Water or (antifreeze or antifreeze) gets into the cylinders, and then into the engine crankcase.
Condensation formation.
Absences Hot gas contains large percentage water, which condenses at the top of the engine, and, as a result, an emulsion occurs on the oil filler cap.

Determining the exact cause of “mayonnaise” is quite difficult. However, in 80 percent this is a breakdown. As a result of this malfunction, the antifreeze present in the cooling system is mixed in the oil channels with the lubrication system.

As a result, an emulsion appears under the oil filler cap. It is worth noting that such oil and antifreeze are no longer suitable for further use. Both components are replaced with new ones. By the way, an emulsion on the oil filler cap (VAZ-2107 is no exception) may occur due to operating conditions. It often occurs in winter and autumn at the first cold snap. This is due to the occurrence of condensation, which forms when the temperature of a warm engine and the outside air from the street differs. When the engine is warmed up, the moisture vapor that has entered the lubricant evaporates and then condenses on the plug. This causes an emulsion to form on the oil filler cap. “Gazelle” rarely suffers from such a “disease”. However, if it is detected, immediate action must be taken.

Checking other places

In addition to the lid, “mayonnaise” may form on the dipstick. This should also be checked. Also the reason is the use bad oil, which does not provide lubricating properties at all.

There are cases when the emulsion on the oil filler cap (photos of it are presented in our article) disappears by itself - during the first warming. But if the problem does not go away long enough, this is a signal indicating a breakdown in the cylinder head. It is through the gasket that these two components - oil and antifreeze - are mixed.

Replacing gaskets on BMW, Skoda, VAZ, Gazelle cars

The process of dismantling the block is the same for all engines (except perhaps for the rotary Mazda and the opposed Subaru). The block head is dismantled along with the receiver and exhaust spider. To perform this operation, several steps must be taken. First, the fuel supply and drain lines are disconnected. Next, the negative is removed from the battery. Using a spanner, remove the hood mounting bolts. Next you need to dismantle front bumper and engine splash guard. Then drain the old coolant. On VAZ, Gazelle and foreign cars (such as Skoda and BMW), it is poured out by unscrewing the tap at the bottom of the radiator. First place a container under it. For passenger cars A 5-liter canister is enough, for Gazelle-type trucks - at least a 10-liter canister. After this, the ignition coils and the plug block of the valve timing sensor are dismantled.

After this, unscrew the bolts and remove the wires from two oil sensors - pressure and emergency pressure. Disconnect the pads from the temperature sensors and coolant heating indicator. After this, the clamp is loosened and the thermostat is removed along with the pipes going to the expansion tank. Next, loosen the tightening of the element going to check valve brake vacuum. Remove the block from the TPS. Then remove the ground wire from the stud on the front of the receiver (usually it blue color). Next, unscrew the nut and pull out the accelerator cable. Disconnect the speed sensor crankshaft. It is secured between the toothed rim of the pulley and the shaft. Remove the block between the engine intake pipes. Slide the oil seal off the threaded end cable and unscrew the cable securing nut. Remove the element from the bracket, which is mounted on the engine intake pipe. For better effect you need to move it back.

The gas pedal cable holder (if it is a VAZ or GAZelle car) is bent and the element is pulled out. Also remove all the wires from the generator, remove the plug block from the IAC (idle air control). Next, the pads are removed temperature sensor, the antifreeze supply pipe from the fitting of the stove-heater is weakened. Now we get to the intake system. We take out the plug blocks from the four injectors, unbend the wire harnesses from the holders and take them out. Next up is the exhaust system: the gases that come from the exhaust manifold are disconnected. The next step will be to dismantle the generator and throttle valve pipes.

Dismantling the block

Remove the camshaft. If the engine is 16-valve, 2 shafts are removed.
The clamp is loosened and the hose is removed from the throttle body.
The thermostat assembly is removed.
The bolts are unscrewed cylinder head mountings along with the washers.
The head is removed along with the gasket.

It is important

Do not under any circumstances use for removing the cylinder head a screwdriver, knives and other improvised objects that can be used to pry out the head. This way you will damage the surface of the element that is adjacent to the block.

Assembly

All that remains is to install new gasket and put everything back in place. Please note that before installation it is coated with red silicone sealant. The surface of the block and head (mating parts) is thoroughly cleaned of the remnants of old sealant, accumulated chips and lubricant.

Look carefully at the matches of the marks. If the gasket is installed upside down, the situation will only get worse. Further installation is carried out in reverse order. After this, the cylinder head is troubleshooted: using a steel ruler and feeler gauges, the flatness of the surface of the head, which is adjacent to the block, is checked. To do this, you need to place a ruler along the element and use feeler gauges to measure the gap between both planes. If it is at least 0.2 mm, the head must be replaced. Be sure to tighten the bolts in a criss-cross pattern. Mandatory: At the first stage, the tightening force is 39-61 Nm. After 2 hours, the second stage is performed. The tightening force is from 130 to 140 Nm.

Final stage

And the last stage is pouring new antifreeze and oil. Now they should not intersect with each other, forming “mayonnaise”. The emulsion on the oil filler cap is no longer a threat to you. By the way, in order to avoid the formation air lock When pouring antifreeze, you should adhere to some pauses. That is, to give it the opportunity to completely drain from expansion tank through the pipes into the radiator.

For greater efficiency, you can park the car on a slope so that the front is higher than the rear. Then all the existing air vents will collect in the expansion tank.

How to prevent the formation of "mayonnaise"?

To prevent the emulsion on the oil filler cap from bothering you, you need to remember one simple rule: do not warm up the engine for a long time. idle speed. In this mode of operation it is practically not used.

Therefore, the formation of condensate - water - occurs. Moreover, the engine does not really warm up at idle.

Conclusion

So, we found out why an emulsion appears on the oil filler cap. Whether you have a Skoda or a Gazelle does not matter, since mayonnaise is equally dangerous for all cars. If the problem does not go away on its own, you should not turn a blind eye to it. You may have had a breakdown cylinder head gaskets. As you can see, you can make the replacement yourself, but if you lack experience or confidence, it is better to entrust this task to professionals.

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 cap of the expansion tank on a slightly cooled or cold unit. A decrease in coolant level without obvious reasons may indicate a malfunction in the cylinder head area, problems with the cylinder head gasket or the cylinder block itself.

Broken or defective gaskets are the most common cause moisture getting into the oil. In other words, the oil contains coolant, which is a mixture of chemical concentrate and water.

The tightness of the gasket is usually broken as a result of normal wear and tear of this element, and after the engine overheats. If overheating previously occurred and the gasket was 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 and constantly operates in conditions high blood pressure. As a rule, the gasket fails at mileage of 100 thousand km. and more. With a broken gasket, the engine runs unevenly and antifreeze leaks out.

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

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

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

The appearance of cracks in the cylinder block or cylinder head can also occur as a result of overheating or temperature changes, or 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, pouring coolant Low quality, a large number of water in relation to the concentrate or antifreeze or antifreeze concentrate incorrectly diluted with water.

We also note that cracks or deformation of the cylinder head can occur if, in severe frosts, you immediately turn off the engine, which was previously operating at the limit. For example, such consequences sometimes result from a sharp stop of a heated unit after driving on the highway at maximum speed. Microcracks in the block and head can also be the result of accidents, aggressive use of the vehicle, driving over serious obstacles, etc.

The possibility of active accumulation of condensate in the internal cavity of the engine crankcase should not be excluded. This occurs when weather or other conditions cause significant temperature changes. During such changes, outside air enters the engine crankcase through the breather and crankcase ventilation system.

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

Strong CPG wear in combination with antifreeze entering the cylinders can also cause the formation of an emulsion. In this case, the coolant not only enters the cylinders, but also drains through piston rings into the crankcase.

As a result, the oil thins, the coolant level drops, and the oil level rises. In this case, the emulsion and loss of the oil’s protective and other properties are clearly noticeable.

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

What's the result?

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

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

After diagnostics, you can be sure of the severity of the problem, as well as the possibility or impossibility. In any case, before carrying out the inspection, you should not hastily decide on the need to replace damaged elements.

Finally, let’s add that if in the cold season a white emulsion is noticeable on the oil filler cap without any other reasons, and the amount of emulsion is very small and the antifreeze does not leave, then to begin with it will be enough to simply change engine oil.

It may also be necessary to reduce the subsequent service interval. With the onset of heat, the problem may disappear on its own, since the car will not be subject to significant temperature changes, and excess moisture will be eliminated from the engine along with replacing the lubricant.

Causes

Emulsions are formed by two immiscible liquids. In most cases, one of the emulsion phases is water. In other words, when engine oil and water are mixed in the engine, you will find a white-yellow coating in the pan, on the dipstick, or on the oil filler cap. There are only 2 reasons for the appearance of emulsion in the engine:

coolant getting into the oil, integral part which is water. An antifreeze leak manifests itself not only as an emulsion, but also as a decrease in the amount of coolant in the tank and an increase in the oil level in the pan;

Under no circumstances continue to operate the vehicle if you find emulsion on the dipstick. In this state, the oil loses its lubricating ability. No less dangerous is engine oil getting into the cooling system, which makes the engine more likely to overheat.

formation of condensation on the oil filler cap in winter time of the year.

White deposits on the oil filler cap

Many drivers are seriously scared when they see a white emulsion on the inside of the lid. But in most cases, their fears are unjustified, since plaque occurs due to the peculiarities of engine operation in the frosty season.

Moisture getting into the ventilation system crankcase gases– a natural process. But when the car is used in the warm season, it has time to evaporate. With the onset of frost, moisture actively condenses on all cooled surfaces. When the engine warms up, this moisture completely evaporates from the surface of the heated parts. But since the oil filler cap does not always have time to heat up in cold weather, condensation accumulates on its inside. Drops of water, mixing with oil vapor, form a yellow emulsion.

In other words, main reason emulsions on the lid - short runs of the car, during which all engine parts do not have time to warm up thoroughly. That is why owners most often notice such plaque in winter, late autumn and early spring. If you find an emulsion on the oil filler cap, but the oil on the dipstick is in normal condition, there is no need to worry. It is enough to wipe the cover and periodically monitor the condition of the oil in the engine.

To reduce the amount of emulsion, periodically drive your car more than a few kilometers from home to work and back. At the same time, we strongly advise against staying for long periods of time.

How can antifreeze get into the oil?

How to determine why antifreeze gets into the oil?

It is quite rare that coolant and oil are mixed in unilaterally. It is more likely that if you find emulsion on the dipstick and under the valve cover, you will find traces of oil in the expansion tank.

When looking for the cause of the emulsion in the engine, we recommend taking the path of least resistance, starting the test with easily accessible units. If your car has an oil heat exchanger, inspect its body for antifreeze leaks and oil fogging. These symptoms may serve as an indirect sign that the cause of the malfunction is in the cooler.

If you find a white emulsion on the dipstick and at the initial stage of the problem, you can limit yourself to flushing the engine by changing the oil n times. For such purposes, you can use even cheap products at mineral based. But even so, it is important to know.

If the entire filling volume of engine oil has turned into an emulsion, without complete disassembly the engine is indispensable. In this case, be sure to blow out the lubrication channels of the crankshaft journals and the oil nozzles of the piston group. The emulsion can clog the channels, which will lead to the unfortunate consequences of oil starvation.

Troubleshooting of the cylinder head, block head and gasket

After removing the cylinder head, carefully inspect the gasket and mating surfaces. Weak areas that cause oil and antifreeze to mix are usually clearly visible on the old gasket.

If the gasket does not cause any complaints, most likely a microcrack has formed in the cylinder head or cylinder head. In the article we talked about how you can test BC at home using kerosene. If possible, we recommend using professional help. As practice shows, only a test on a pressure testing stand can reliably determine the fact of leakage of liners, oil circulation channels, and coolant.

Features of the VAZ cylinder head

The design of the cylinder heads installed on VAZ 2101, 2102, 2103, 2104, 2105, 2106, 2107 engines has aluminum plugs. In rare cases, these plugs are destroyed, allowing antifreeze access to the cylinder head. Therefore, owners of these car models should remember the reason, uncharacteristic for most cars, that an emulsion appears on the dipstick and inside the engine.

Car service specialists, as well as car manufacturers, recommend changing the oil in gasoline or diesel engines every 10 thousand kilometers. But even if you follow these regulations, 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 “mayonnaise” may vary. Let's look at the reasons for this phenomenon, and also find out how to deal with the problem.

What is white emulsion?

Modern motor oils, which are sold everywhere today, are made on a hydrocarbon basis. When gasoline burns, various substances are formed. These are antifreeze, water, alcohols, acids, and peroxides. All these substances in the hydrocarbons mix, resulting in the formation of a white emulsion on the oil filler cap. Why does she appear here? It's simple - due to the huge number of microscopic bubbles, the emulsion has a white color in case of severe contamination of the oil. The filler cap and dipstick are one of the coldest places.

Therefore, “mayonnaise” sticks well to these surfaces.

Causes

Automotive service specialists experienced car enthusiasts They say that there are a huge number of reasons for the appearance of emulsion. Most often, this white mixture can occur when the crankcase power unit coolant gets in. This can happen due to a 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 head. Another one of possible reasons antifreeze getting into the crankcase - 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 in the upper part of the engine. As a result, a white emulsion accumulates on the oil filler cap. It is quite difficult to figure out the exact reason why this “mayonnaise” that frightens many car enthusiasts occurs. But in most cases this is due to a breakdown of the cylinder head gasket. Because of this, coolant flows freely into oil channels and there it mixes with oil. It should be noted that if antifreeze gets into the lubricant, it can no longer be used. Both the oil and coolant need to be changed. 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 operating conditions are violated. Car enthusiasts often encounter “mayonnaise” different colors at the first drop in temperature - in autumn and winter. But there is no need to sound the alarm. This is condensation that occurs due to the temperature difference between a warm engine and the air outside. When the engine warms up, then the moisture in the oil will evaporate, but some of it will accumulate in the form of condensation on the neck plug. What’s interesting: many cars are susceptible to this disease, but the Gazelle practically does not suffer from it.

Possible consequences

When in lubricants If water, condensate or coolant gets in, the oil quickly loses its properties. Accordingly, lubricating properties are reduced. In winter, oils can even crystallize, which will not have the best effect on engine performance. The film between the rubbing pairs of parts leads to rapid wear each and every part in the engine.

Most often in these cases the engine simply jams, and this is an expensive repair. Therefore, if an emulsion has formed on the oil filler cap, the reasons should be carefully examined. It is urgent to find the problem and fix it.

More about condensate

Even those who store their cars in a garage face this problem. But most often it bothers those who park their cars in the yard. If a car regularly spends the night outside in the fall during the rainy season, then a large amount of water vapor may well enter the crankcase cavity. They condense in pipes and on oily surfaces. At one time, 1-2 g of condensate can enter the motor. This is quite enough to form an emulsion on the oil filler cap. By the way, bubbles will also be visible on the dipstick. In winter, the owner will see “mayonnaise” very often. If the car is constantly driven 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 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 dipstick 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 thing is that the oil is clean and there is no antifreeze in it. If you fix the crankcase ventilation system, then you won’t even have to replace lubricants.

Coolant: serious case

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

Diagnostics

To check these reasons, the lubricating fluid is drained from a sufficiently warm engine into a prepared container. In hot oil, traces of coolant will be visible even to the naked eye, 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 liquid will be sucked up by the oil receiver. If a yellow emulsion has formed on the oil filler cap, then it is better to temporarily stop using the car. The viscous mixture will clog the channels for the movement of lubricant. Connecting rod bearings, piston rings, main bearings with such liquid will quickly fail.

Bad 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, fuel sometimes contains kerosene, alcohol, water and other ingredients. Conclusion - to prevent the formation of “mayonnaise” in the engine, it is better to refuel at proven gas stations.

Cylinder head gasket failure

If emulsion is visible on the oil filler cap, the reasons are often a leaky gasket. A breakdown is possible due to burnout due to overheating or as a result of physical obsolescence and wear of the gasket. But such cases occur only on old engines that have not been monitored. The main sign of a breakdown is unstable work motor. The coolant leaving the expansion tank will also be noticeable. If you carry out diagnostics in a timely manner, then you can limit yourself to only 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 freezing of antifreeze. It is necessary to monitor the characteristics of the coolant operating temperatures. 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 cylinder head crack. Also, engines are deformed due to mechanical shocks. If there was a frontal impact on the car, you should not exclude the possibility of cracks appearing on the block.

Water in the engine sump

This problem can only be resolved by complete replacement lubricating fluid. It is best to flush the engine using specialized substances. 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 only possible 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 the problem is not corrected in time, you may end up with expensive repairs. At the first sign that an emulsion forms on the oil filler cap (whether it is condensation or not does not matter), you need to immediately take the necessary measures.

Often in winter, during severe frosts, car owners who at least occasionally look under the hood of their car and check the engine oil level may have observed a strange whitish-brown coating. It usually occurs on the oil filler cap and directly on the dipstick itself.U inexperienced drivers this causes serious concern, while others unknowingly rush to the blthe nearest service station, and there already experienced guys can “sentence” the engine and simply change the cylinder head gasket unnecessarily, but for the client’s money.

Actually, what kind of misfortune is this and what danger does it pose to the engine? I immediately hasten to reassure everyone: uh a water and oil emulsion that has a yellowish-brown foam color It does not pose any danger to the internal combustion engine! This is ordinary condensate, i.e. liquid formed by condensation of gas or vapor. Where does it come from? Of course, from the moist air that enters the engine. This is why “white plaque” often occurs during the cold autumn-winter-spring period.

An emulsion forms in the crankcase ventilation system. I will not dwell on the SVKG in detail, I will only note that the operation of your car’s engine largely depends on its proper functioning, the same oil consumption, throttle response. In short, the ventilation system is designed to equalize the pressure in the crankcase (exhaust crankcase gases) with atmospheric pressure, which avoids oil leaks from the cylinder head gasket, oil seals, and even squeezing out the oil dipstick.

In particular, car owners BMW We often encountered the need to replace the crankcase ventilation valve (CVVV). This valve serves to regulate the pressure entering the intake manifold crankcase gases. When the vacuum is low, the valve is open. When there is significant vacuum in the inlet channel, the valve closes.

This is what the VKG kit looks like for BMW engine M52TU. Cost official dealer- 3.5 million rubles

Most often the membrane wears out KVKG. Over time, it becomes dull and breaks, as a result of which a malfunction occurs in the operation of the car engine (approx. speed fluctuates, acceleration dynamics decrease). But we will return to the formation of “white plaque”.

Worn KVKG membrane

So, hot crankcase gases , which are formed in the SVK, contain water vapor. Let's remember the chemistry course: when complete combustion hydrocarbon fuel The end products are carbon dioxide (CO2) and water vapor. So, these same crankcase gases ( approx. or rather water vapor from them) and condense on the cold engine valve cover, as well as its other cold parts and, in contact with the oil, form an emulsion.

Here we come to a very important conclusion.

Membranes for the VKG valve are purchased separately As you know, the engine often runs in winter for a short time and does not warm up completely (it’s good if we drive 10 km to work in the morning). And exactly in an unheated state, quite a lot of white emulsion can form, and it becomes noticeable.to the attentive car owner As a conclusion: white plaque is the result short runs in cold weather . We are not talking about any problems. This is actually confirmed specialists

"official Volkswagen service. White emulsion on the dipstick and oil filler cap - this is normal in our winter conditions and nothing needs to be done. The emulsion is formed due to moisture condensation on the fastest cooling parts of the engine (valve cover and dipstick). There is only one recommendation - give the engine the opportunity to warm up until operating temperature. The greater the condensation, the more often there are short trips in cold weather (approx. without warming up the engine to operating temperature), Head of the service department of the official importer of Volkswagen "Atlant-M Farzeughandel" Vladimir Voiteshonok. - The deposits themselves do not cause any harm. Regarding possible complications in internal combustion engine operation, then this question is more extensive. Short trips to cold weather without sufficient warming up they lead to rapid wear of engine parts. Therefore, in such operating conditions, it is necessary to at least change the engine oil more often and try to reduce trips over short distances."

How to deal with emulsion? First of all, it's not worth it take a long time to warm up in winter engine at idle speed. The point is that on Idling rpm the crankcase ventilation system is little involved, also full warm up at idle will take a very long time.

It is necessary to start driving after a short warm-up in 5-7 minutes. I brushed the snow off the car and drove off! On the road, at gentle speeds, the engine will reach its optimal operating temperature much faster than when the car is parked for a long time. IN other things , such advice is indicated in instruction manual car, it is also asked to be used in practice by specialists from official services.

If you suspect a breakdown of the cylinder head gasket and, as a result, gases or antifreeze entering the oil system, then to do this you should inspect the radiator of a warm car for the presence of bubbles, as well as the crankcase of a warm engine for the presence of significant white deposits directly into himself crankcase. As a rule, on valve cover the emulsion disappears after the engine has been running under load for a long time . For example, long trip Without stops at a speed of 100-120 km/h leads to its disappearance.

If a white coating is found above the measurement divisions, there is nothing to worry about

If a rich emulsion is detected on oil dipstickhigher measuring divisions, that is no cause for concern: crankcase gases break out and mix with the oil when decrease in temperature leads to the formation of condensation . But if white foam or a thick layer of plaque appears on the dipstick, then this is a minimum a good reason to take a closer look at the condition of the engine.

But such a white coating should raise suspicion

It is also important to pay attention to color exhaust smoke. If it is thick and white, then there is a possibility of mixing oil and antifreeze as a result of a breakdown of the cylinder head gasket very high . It would also be a good idea to monitor the antifreeze level.. If there is less antifreeze, and the oil level, on the contrary, has increased, you will, at a minimum, have to remove the cylinder head, replace the gasket and valve stem seals. But it’s even worse when antifreeze gets into the combustion chamber and causes corrosion of the cylinder liner walls. Serious repairs cannot be avoided here.

Normal oil level on dipstick

If its level has not increased, there is very little plaque, and there is no less antifreeze, and in addition an emulsion has appeared on the oil filler neck cap, it is quite possible that the reason for this was low quality oil or condensation of moisture trapped in it. Again, this is a common occurrence in winter. does not require emergency measures and goes away on its own as the temperature increases.

Dmitry Makarevich