What causes oil in antifreeze? Oil in antifreeze - unpleasant consequences for the engine

Engine fluid getting into the cooling system is a common problem for American-made cars, but it is also common in domestic cars. We will tell you how oil ends up in antifreeze; the cause of such breakdowns is of interest to many car enthusiasts.

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Causes

As a rule, about a problem such as engine oil in the coolant expansion tank, the driver knows when it decides in the system. There may be oil residues on the neck, and the coolant itself may change its color or consistency. In addition, the refrigerant may develop a relatively unpleasant odor.

One way or another, you need to keep in mind that mixing lubricant and refrigerant is a very bad sign for the owner vehicle. Both consumables circulate through systems isolated from each other. Moreover, they are sealed, so mixing liquids should at least alert the driver. If consumables are mixed with each other, this means that the systems are no longer sealed, which can cause engine fluid to leak.

The most likely and common reason for the mixing of consumables, in particular the ingress of engine fluid, can be:

• occurrence of mechanical damage to the operation of the oil radiator or oil cooler;
• malfunction of the cylinder head (the block gasket has expired);
• The heat exchanger (oil cooler) gasket has exhausted its service life.

It should be noted here that it is at these points that the lubrication and cooling systems come into contact with each other. In an oil cooler, such contact is explained directly by the purpose of the device. In some vehicles motor fluid it simply must be maintained at a certain temperature, as a result of which the machines are equipped with an oil cooler. The latter, in turn, directly interacts with the vehicle’s cooling system, where the refrigerant acts as a coolant.

As soon as even the slightest depressurization occurs in the system or the pipes or hoses are damaged, engine fluid will immediately begin to enter the cooling system or vice versa.

In addition, one of the important reasons is the inconsistency of the refrigerants that the driver pours into the system of his car. For example, the driver recorded too low level refrigerant in the expansion tank and found no other way out than to pour the first available antifreeze into the system. As you know, antifreeze manufacturers can use various additives in their products. If these substances are incompatible with each other, then when heated with the engine, they enter into contact with each other. chemical reaction.

How to determine the mixing of engine fluid and coolant?

The following are the reasons why you can determine that oil and refrigerant have mixed in your car:

How to solve a problem?

So, if the reason for mixing consumables is mechanical damage to the oil cooler gasket, then it is necessary to replace it.

What will you need?

For this you will need:

• about 12-15 liters of distilled water;
• new oil cooler gasket;
• new antifreeze;
• container for collecting old refrigerant.

Step-by-step instruction

So, let's start replacing:

1. If possible, add a special cleaning fluid to the refrigerant. Start the engine and let it run for a while (no more than 10 minutes). It is necessary for the engine to warm up to operating temperature, wait until the cooling fan starts. It is recommended to flush the system before replacing the oil cooler gaskets.
2. After washing, find the antifreeze drain plug under the bottom of the car. Place an old basin or any other container under it, unscrew the lid and drain the used refrigerant.
3. After this, you need to dismantle the oil cooler. For each individual vehicle, instructions for disassembling the oil cooler may differ, so we recommend that you use the service book for your car. After disassembling the unit, you need to clean it completely. Remove old gaskets that have expired and install new ones in their place. Buy gaskets according to your car model. If you don't know which one is best to buy, consult your dealer.
4. Having replaced the gasket, you can begin to remove the refrigerant expansion tank. Rinse it as much as possible. You won't be able to wash it completely, so if you care too much about it... appearance, then you can replace the tank with a new one.
5. When the coolant is drained and the expansion tank is flushed, you need to flush the system several more times. Replace the tank and fill it with distilled water. Start the engine and turn off the air flow inside the car. Also turn on all voltage consumers to maximum so that the motor warms up faster. When the temperature internal combustion engine operation rises to 100 degrees, the fan turns on cooling system.
   Let the engine run for about 10 minutes, while turning off all voltage consumers and turning on the interior airflow. The motor will begin to cool slightly and the cooling fan will turn off. Wait about 15 minutes for the motor to cool slightly, otherwise you may get burned when draining the distillate. Drain the distilled water and repeat the procedure at least one more time. The system must be flushed until the drained distillate becomes almost transparent. Of course, it should be free of any traces of motor fluid.
6. After this, you can tighten the drain plug and fill in fresh antifreeze. Use only original products recommended by automobile manufacturer. If you purchase a counterfeit, this may be fraught with other problems.
7. Start the engine and press the gas pedal firmly several times. At this point you will need the help of another person. When you press on the gas, an assistant should squeeze the cooling system pipes. In this case, the expansion tank cap must be closed. This is done in order to prevent the occurrence of air jams and eliminate those that have already appeared in the system. Open the expansion tank cap from time to time to release any trapped air.

Engine oil and coolant have different functions in the engine and never overlap. But under certain circumstances, antifreeze penetrates the lubrication system or, conversely, oil enters the cooling system. This compromises performance power unit.

To avoid unpleasant consequences by recognizing a malfunction at an early stage, it is advisable for every car enthusiast to know about characteristic features presence of antifreeze in engine oil. Moreover, it is unlikely that such a manifestation will be overlooked.

Experienced auto repairmen in such cases say: “Knock off the cylinder block.” And, as a rule, they turn out to be right. Through a microcrack in the block, some of the oil seeps out under pressure, forming an emulsion in the cooling system. The recipe for engine treatment for car owners sounds like a death sentence. Because replacing a cylinder block is a labor-intensive and expensive operation. And it’s not a fact that the old cylinder head will successfully “grow together” with the new block; then the motor assembly will have to be replaced. And this is a topic for a separate article.

Signs of antifreeze in oil

The malfunction will make itself known by showing characteristic signals. Signs of antifreeze getting into the oil are:

If you realize that antifreeze has leaked into the oil, immediately stop the engine until the cause is determined. Otherwise, there is a chance of getting into an expensive one.

What to do if antifreeze gets into the oil

Replacing the cylinder head

First, determine the exact cause, and then decide what to do next. In most cases, it is enough to replace the gasket with a new one after inspecting the engine parts. If the block head is in good condition, without visible cracks and holes, then repairs will be inexpensive. And if there are obvious defects, the “tired” part of the engine will have to be replaced.

Advice! Repairing an old block head is impractical. If this is the cause of the leak, then it is better to install a new one.

After eliminating the root cause, the cooling and lubrication system will need to be completely flushed. You will have to disassemble all the pipes and clean the channels. This procedure is quite labor-intensive, because the mixture of antifreeze and oil is difficult to wash off from the parts. After physical cleaning of all accessible places, special flushing liquids are poured in, with the help of which the system is cleaned of all kinds of contaminants.

The consequences of mixing antifreeze and oil

The result of engine contamination with a mixture of two technical fluids will depend on the duration of exposure. First, coking of the bearings occurs, deposition of sticky oil on the internal parts, and corrosion. If you do not pay attention to the signs of malfunction for a long time, then eventually the engine will seize and then only a major overhaul will bring the engine back to life.

When buying a car, be prepared for the fact that you will have to do basic maintenance yourself. Moreover, all recommendations are described in the operating instructions. Having studied the basic knowledge of the machine's structure, you are unlikely to manage to pour coolant into the lubrication system. And knowing how to determine antifreeze in oil, you will not miss an insidious problem.

Car owners often face the problem of engine oil getting into the car's cooling system. Oil in antifreeze - bad sign, such mixing of oil and antifreeze is unacceptable. Inside the car, their movement occurs through independent, sealed and isolated systems.

Why is this happening

There are different signs: damage to the oil cooler or a problem with the cylinder head. Contact between the cooling and oil systems occurs only at these points. Some cars need to maintain a specific oil temperature from seventy-five to eighty-five degrees. Such vehicles are equipped with an oil cooler that interacts with the cooling system, and the coolant is antifreeze.

Oil in the antifreeze indicates that you will need to sort out the oil cooler and fix the problem, or you will have to change everything completely. Lubricating properties are lost, a large load is placed on the engine, which eventually fails. The antifreeze composition contains glycol with toxic indications, so when it gets into the engine lubricant, the potential is destroyed. This leads to blockage of oil molecules and lubricating properties.

Causes and solutions to the problem:

• the head gasket is broken - remove the head and replace the gasket;
• deformation of the head plane – grinding (milling work);
• Poor tightening of bolts - tighten using a torque wrench;
• microcrack in the cylinder block - repair with epoxy paste, clean the surface, weld, weld steel.

The reason for oil getting into the antifreeze is a burnt gasket or a faulty cylinder head itself. This problem comes up when drivers start checking the fluid level. The color and thickness of the coolant changes, the refrigerant develops a pungent odor. This is the “first call” for the car driver.

Today, ethylene glycol is used as a base for coolants. It is diluted with water in certain proportions, but has the disadvantage of toxicity.

Lower boiling point, but best quality propylene glycol liquids, although their production requires more costs.

If the system depressurizes or the pipes are damaged, the engine fluid instantly ends up in the cooling system and vice versa. There are many factors that cause this problem. One of the most important is the inadequacy of the refrigerants used by the driver of the vehicle.

Problem Definition

It can be quite difficult to determine with accuracy why oil gets into the antifreeze. Basically, this problem is identified by white smoke from the exhaust pipe. The quality of the oil is great importance. If the oil dipstick has a white coating, this indicates the presence of this problem. The best solution for drivers is, of course, to turn to specialists. To identify the problem, use a special luminous additive. It helps to determine the exact locations of cracks, depressurization and other deficiencies. When the problem cannot be solved in this way, the entire cooling system and some engine parts are gradually disassembled. All parts undergo diagnostics for all kinds of breakdowns and malfunctions.

After detecting oil in antifreeze, you need to determine the cause of its appearance, do testing and eliminate this deficiency. To prevent oil from getting into the antifreeze, it is necessary to regularly monitor the liquid level, color and condition. When a breakdown is detected, it allows you to save on repairs and minimize all consequences. Sometimes the situation can still be saved by replacing the gasket, crimping and grinding the cylinder head, as well as replacing the valve stem seals.

What can happen:

• decline bandwidth filters;
• formation of balls with ethylene glycol and oil;
• the formation of acids that cause chemical destruction and corrosion;
• decrease in antifriction properties;
• worn out sliding bearings.

Oil getting into the coolant is associated with the cylinder block. An experienced motorist immediately determines that this is a burnt gasket.

The consequence is a change in the color and saturation of the exhaust gases, a decrease in the level of coolant fluid in the distribution tank.

The above information suggests that the reasons for oil getting into the antifreeze are few. Although the consequences can be catastrophic for the vehicle engine. It is necessary to carry out a visual inspection of parts every day and regular maintenance of the vehicle. Don't ignore the problem and warning signs from the inside of your vehicle. The slightest defects and breakdowns must be eliminated immediately by contacting specialized service centers or at the station Maintenance.

Mixing motor lubricant with engine coolant is a critical malfunction that requires immediate intervention and elimination. In other words, the car cannot be operated, only repaired. Although infrequent, this problem occurs on new and used cars. To avoid costly repairs, the car owner must clearly understand the procedure for his actions when oil is found in antifreeze.

How does lubricant get into antifreeze (antifreeze)?

The cooling system of the power unit is a network of channels passing through the block and cylinder head. It is sealed and therefore operates under pressure resulting from the heating and expansion of the liquid. The lubrication system has a similar structure, only the channels are narrower, and the pressure is created by an oil pump.

There are only 3 reasons why two different liquids are mixed:

1. Gasket between head and cylinder block – weakness any motor. When the smallest crack appears in it, the liquid with more high pressure penetrates into a “foreign” system. As a rule, oil enters the antifreeze because the oil pump “presses” harder than the pump. Although mutual penetration also happens.
2. In cars with powerful and more complex engines, there is an element for cooling the engine lubricant - an oil cooler. In it, too, mixing of antifreeze and oil occurs as a result of a breakdown of the gasket.
3. Cracks in the metal of the cylinder head itself.

Now about why the integrity of the gaskets is compromised. The main enemy of any motor and additional elements- this is overheating. From exposure high temperature the aluminum cylinder head or oil heat exchanger housing is deformed. But since the part is firmly held by bolts, longitudinal expansion of the metal occurs, pulling the gasket along with it. Cracks appear in the latter, where the lubricant penetrates.

The opposite situation also happens: antifreeze flows into the engine and dilutes the oil in the crankcase. The reason is a malfunction of the pressure relief valve installed in the expansion tank plug. Then antifreeze penetrates through the cracks, since its pressure is greater.

Fault detection

This problem, or rather, a serious breakdown, is quite insidious and does not appear immediately. Liquid lubricant passes through microcracks in small portions, without having a particular effect on the operation of the power unit. Changes become noticeable at the next stage, when the channel connecting the two systems expands and the mixing speed increases.

How to determine whether lubricant has gotten into antifreeze:

• due to the deterioration of the cooling properties of antifreeze, the engine begins to heat up more often, the electric fan operates more often;
• the oil level gradually decreases, and the antifreeze level increases (it’s quite difficult to notice);
• the pump impeller whips up the oil-water mixture, turning it into a thick white emulsion that clogs the filter, causing the engine lubricant pressure to drop;
• drips are visible on the outside of the block or heat exchanger body, originating near the gasket (they do not always appear);
• the oil in the expansion tank changes the color and consistency of the coolant.

Important! The most obvious sign of mixing, monitored visually, is the emulsion white in an expansion tank with antifreeze. If you find a similar substance in the tank, compare this fact with other symptoms - constant overheating of the engine and signals from the oil level warning lamp.

As a rule, trouble does not come alone. Antifreeze that gets into the oil pan can create serious problems: at best, the emulsion will clog the lubricating channels and filter. Worst case scenario crankshaft will rotate the bearings (sliding bearings) as a result oil starvation. Expensive repairs are guaranteed.

Often the gasket bursts all the way to the cylinder walls, after which antifreeze gets into the combustion chambers (its channels are closer). The sign of a breakdown is clearly visible - white smoke pours out of the exhaust pipe in large quantities, and the engine power drops sharply.

When a similar problem occurs on a machine equipped with a heat exchanger - a motor lubricant cooler, diagnostic difficulties arise. If external signs If there are no drips, then after identifying the emulsion in the expansion tank, it is better to contact a car service center. There, both units will be purged with a special installation and the culprit will be determined by air leakage.

Elimination method

When a significant amount of lubricant gets into the antifreeze, the latter is unable to work as a coolant. It forms clots and even solid particles that settle on the walls of the channels, clogging the thermostat valve and clogging the radiator. There is also no guarantee that mutual penetration has not occurred and antifreeze has not leaked into the oil pan. Hence the conclusion: both fluids must be drained.

If your car is equipped with an oil cooler, immediately contact a service station to locate the broken gasket. Then decide whether to carry out the repairs yourself or entrust the work to car service personnel.

What to do if oil or emulsion is found in the expansion tank with antifreeze:

1. Both systems need to be flushed. Before draining the antifreeze, add a special detergent composition to the expansion tank and let the engine run at idle speed 5 minutes. Empty the lubrication system immediately.
2. Unscrew and throw away oil filter.
3. Replace the gasket on the cylinder block by removing the cylinder head. During the dismantling process, disassemble the elements of the cooling system (pipes, pump, thermostat) and thoroughly rinse them by hand. Do the same with the heat exchanger if it is the culprit for mixing liquids.
4. Unscrew the oil pan and oil pump, disassemble the latter and change all gaskets. Before assembly, wash the parts with gasoline or solvent.
5. Assemble the power unit, install a new filter and fill in the flushing fluid motor lubricant. Instead of antifreeze, fill the system with distilled water and add detergent.
6. Start the engine and let it run for 10–15 minutes without increasing the speed. Follow indicator lamp oil and temperature indicator.
7. When finished, replace the water. working fluid- antifreeze, and flushing oil - full-fledged motor oil. It is highly advisable to change the filter twice.

Advice. When pre-flushing the cooling system before eliminating the malfunction, monitor the temperature and pressure of the lubricant. If you notice something is wrong, immediately turn off the engine, as the oil still gets into the antifreeze.

No matter how carefully you try to wash the engine parts during disassembly, you will not be able to get to all the channels. Therefore, flushing is performed several times, including after starting the power unit. During further operation, monitor the condition of the process fluids so that the problem does not recur.

At normal operation Engine oil and coolant move along different lines and do not intersect with each other. When some engine components fail, a malfunction occurs in which oil gets into the antifreeze. If such a situation occurs, it is necessary to determine the cause of the breakdown and know how to eliminate it.

Signs and causes of oil getting into antifreeze, why it is dangerous

The presence of oil in the cooling system is indicated by a number of signs that every driver should know. Since these liquids should not intersect with each other, it does not matter how much lubricant gets into the antifreeze. Any amount of it indicates the presence of a problem, therefore, in order to prevent expensive repairs, it is necessary to urgently identify and eliminate the cause.

Main features:

If the described symptoms appear, you must urgently look for the cause of such a malfunction. For all cars, the reasons for mixing oil and coolant will be the same, regardless of whether they have a gasoline or diesel engine.

Main reasons:

• cylinder head malfunctions: cracks, deformation;
• damage to the cylinder head gasket;
• pump breakdown;
• failure of the oil cooler or oil cooler;
• sleeve corrosion;
• damage to the heat exchanger gasket or its wear;
• malfunction of the radiator and pipes;
• damage to the oil lines of the lubrication system.

Often, when the fluid level in the cooling system drops, drivers add what they have on hand. If the characteristics of the antifreeze do not match, a reaction can occur that leads to damage to the lines and elements of the cooling system, and oil begins to enter it.

If you do not pay attention to the signs of oil penetration into the antifreeze and do not take timely measures to eliminate the problem, this will lead to more serious consequences:

• rapid wear of bearings, as they operate in an inappropriate environment;
• Corrosion of the cylinder walls occurs. Antifreeze begins to enter the combustion chamber, this leads to hydraulic shock, leading to jamming of the engine;
• mixing oil and antifreeze causes a reaction that causes new growths to appear, they enter the oil filter and clog it. The engine lubrication process is disrupted;
• the oil increases the viscosity of the coolant and the engine begins to overheat.

Video: reasons for mixing oil and antifreeze

Destruction of the oil line in the cylinder block

When the car is running, the oil in the lubrication system is under high pressure. If cracks appear in the system, it begins to mix with antifreeze. The radiator honeycombs begin to become clogged, the engine overheats and this can lead to it jamming.

Such a malfunction can only be determined after complete disassembly of the motor. Diagnostics is carried out by checking the engine in water under high air pressure. Special equipment is used for this. In places where the lines are damaged, air will escape. Troubleshooting is carried out by installing a metal tube into the damaged line. This procedure can only be done by specialists at a service station where the necessary equipment is available. If this fails, you will have to completely replace the cylinder block.

Cylinder head gasket wear

When the integrity of the cylinder head gasket is compromised, the oil and antifreeze supply channels are connected and these fluids are mixed. Timely replacement of the cylinder head gasket can solve the problem. Usually, grinding of the head is also required, as its geometry changes. It is better to grind the head using special equipment. Some craftsmen do this at home. They use a new emery wheel for this, rubbing the surface to be leveled with its flat side. In this way, it will not be possible to achieve uniform removal of the metal layer and it is not recommended. After this, a gasket is selected in accordance with the amount of metal removed during grinding.

The principle of replacing the cylinder head gasket for different cars mobile phones will be the same:

Cracks in the cylinder head body

If oil gets into the antifreeze on an engine that does not have an oil separator, then most likely the reason is a cracked cylinder head. To identify the malfunction, you will have to remove the head and, while crimping it, determine the location of the damage. If there is normal access to the crack, then it is welded using argon welding, but not every service station has it. In addition, after welding work, it is necessary to clean the restored area and grind it. Only a specialist can do such work efficiently. In the case where there is no access to the damage site, the cylinder head will have to be replaced.

If a crack appears in the cylinder, you will not be able to identify and deal with the problem yourself. In this case, you need to contact specialists. At the stand they will be able to determine the location of the damage. The repair consists of sleeving the block. This can only be done at a service station in two ways:

• cooling of the liner with liquid nitrogen;
• block heating.

After this, the hole in the block is lubricated with sealant and the sleeve is pressed into place.

Heat exchanger gasket wear

The problem may arise if the sealing elements of the heat exchanger (oil cooler) are not sealed. To fix the problem, you need to drain the antifreeze, remove the heat exchanger, rinse and clean everything well. All gaskets are replaced with new ones. You should not skimp on this, even if it seems to you that the gasket is still normal.

If there are cracks on the heat exchanger, it will have to be replaced. Before dismantling the heat exchanger, several flushes of the cooling system are performed. To do this, use distilled water until it is completely clean when drained.

Other reasons

In addition to the reasons described, the appearance of oil in antifreeze can occur in the following cases:

1. Cylinder head deformation. This happens when the engine overheats. The malfunction is eliminated by grinding the head.
2. Damage to pipes. Once damaged parts are identified, they must be replaced.
3. Worn water pump. If the cause is a faulty water pump, it will have to be removed and a new one installed.

Troubleshooting

You can fix some problems yourself. If oil in the antifreeze appears due to problems with the oil cooler gasket, then it is replaced as follows:

1. Flushing the cooling system. Add a special liquid to the radiator and start the engine. After it has been running for 5–10 minutes, the fan will turn on, this will indicate that the engine is warmed up, after which it will be turned off.
2. Draining waste fluid. Unscrew the cap on the radiator and drain the liquid into a prepared container.
3. Removing the oil cooler. The sequence of work will differ on different cars, so it is performed in accordance with the design of the car.
4. Disassembling and cleaning the oil cooler. Remove worn gaskets and install new ones.
5. Rinsing and cleaning the expansion tank.
6. Installation of tank and oil cooler. The removed parts are put back in place.
7. Repeated rinsing. This is done using distilled water. It is poured into the cooling system, the engine is warmed up and drained. Perform the procedure several times until clean water drains out.
8. Filling with coolant. After this, you need to remove the resulting plugs. The engine starts and one person must press the accelerator to increase engine speed, while the second person must compress the cooling system pipe. The expansion tank cap must be closed. After this, the lid is opened and excess air is released.

Video: replacing heat exchanger gaskets

Is it possible to drive with oily antifreeze?

If signs of oil getting into the cooling system are detected, the car can be driven only to get home or the nearest service station. It is necessary to eliminate the identified malfunction as quickly as possible. Operating a car in which lubricant and antifreeze are mixed for a long time will lead to serious damage, so you need to act quickly to get out of the situation with minimal consequences and minimal expenditure of money.

To avoid such problems, if it is necessary to add antifreeze, you should use only the same liquid as has already been filled. It is necessary to monitor technical condition car. If you find signs indicating that oil is entering the cooling system, you need to find the cause and eliminate it immediately. If you can’t do this yourself, you need to turn to specialists.