Oil in the intake manifold - causes and solutions

In a car, all components and mechanisms must work correctly; this is how it will be a joy to operate the car. If minor faults are detected and corrected in a timely manner, you can avoid costly repairs in the future. Also, this approach to maintenance is the key to safe use of the car. It often happens that oil appears in the intake manifold. Let's figure out why this happens, how to diagnose and then fix this malfunction.

Why does oil get into the air filter?

There are frequent cases when, while replacing the air filter, the driver detects traces of engine oil on it.
Sometimes, this is detected due to signs of improper functioning of the air filter, the service life of which has not yet expired. If you find that oil is leaking onto the filter element, it is highly not recommended to continue using it, as this can lead to car engine malfunction. But, after installing a new air filter, the problem will not disappear, since after some time marks will also appear on it. Therefore, it is necessary to eliminate the cause of the appearance of engine oil.

Among the most common reasons why oil flows into the air filter are:

1. If there is a malfunction in the engine, or its partial wear, gases that carry particles of engine oil can enter the air filter, and engine gases settle on it;
2. Faulty piston rings. In this case, in addition to the air filter, oil enters the crankcase, as well as into the ventilation duct;
3. Clogged hose that is used to supply oil;
4. Malfunction of the pipe, as a result of which the oil mixes with gases;
5. Clogging of the air filter itself, due to which the units do not receive the required amount of incoming air due to which the engine “chokes”, as a result of which it compensates for its lack from various sources;
6. Severe wear of the oil seals, resulting in increased engine oil consumption;
7. Excessive pressure of crankcase gases.

Whiteness of smoke

After warming up the engine in warm weather, a thick white cloud may appear from the exhaust pipe. It indicates that coolant has entered the cylinders. This happens due to a leak in the gasket between the cylinder block and the head, or cracks in the coolant passages.

It is worth paying attention to other possible causes of white smoke. With the engine turned off, check for exhaust gases entering the cooling system. To do this, remove the expansion tank cap or unscrew the radiator cap. This determines:

presence of exhaust odors; is there an oily film in the liquid itself; Is the coolant level low?

The entry of gases into the cooling system leads to an increase in pressure. After the engine stops, the coolant partially goes into the cylinders. Its level in the tank decreases. Antifreeze (antifreeze) seeps through the piston rings into the oil pan. There it mixes with motor lubricant, diluting it. A kind of emulsion is formed. Motor oil changes color, becomes cloudy, and loses its working properties.

Experienced technicians advise flushing the inside of the engine with diesel fuel before repairing such damage. This saves nerves and time during repairs. A cleaned motor will make it easier to locate the fault.

Additionally, diagnosing the condition of the oil filler plug and cylinder head cover helps ensure that coolant penetrates into the lubrication system. A light foam with a yellowish tint forms on their inner side. A similar sign can be recorded on the oil dipstick.

Low-quality antifreeze can provoke internal corrosion of metal engine parts. Sometimes the damage becomes through, and rust particles get into the expansion tank. Significant funds will be required to restore such an engine.

Engine overheating is a prerequisite for the appearance of white smoke.

The reasons for the appearance of abundant white smoke often lie in engine overheating. Ineffective operation of the system responsible for cooling the engine leads not only to overheating of the power unit, but also to deformation of the piston rings. The consequences require an immediate response and immediate troubleshooting.

If there is white smoke, you will definitely need to check the condition:

• problem cylinder;
• thermostat;
• fan and sensor for turning it on;
• expansion tank plugs;
• intake manifold gaskets;
• cooling system hoses;
• radiator tightness.

Liquid may enter the combustion chamber. This leads to the formation of air pockets and a large amount of liquid entering the cylinders. The consequence may be water hammer. Then pressure surges lead to the formation of cracks in the body of certain parts and damage to various equipment elements.

Having established the specific reasons for the appearance of white smoke from the exhaust pipe, repairs should be started immediately. The consequences of malfunctions will have to be eliminated in the operation of the entire cooling system.

Signs that oil is getting into the intake manifold

Before you say that there is oil in the intake manifold, you must be absolutely sure that this is the reason for the unstable operation. There are a number of signs that clearly indicate this defect:

• Unusual color of exhaust gases. When oil enters the intake manifold, the smoke from the pipe becomes black or bluish.
• When this defect occurs, the motor increasingly overheats. Moreover, it is not related to the load.
• Thrust drops greatly.
• Fuel and oil consumption increases significantly.
• The motor starts to run too noisy.

Common mistakes

When cleaning the damper, motorists often make the same mistakes.

It is important to remember what you cannot do in such a situation:

• at the first opportunity, when there are signs of unstable operation of the internal combustion engine, clean the damper;
• clean the unit without removing it from the car;
• use rough metal brushes and scrapers;
• do not adjust the speed after cleaning;
• remove molybdenum coating;
• make great efforts when cleaning.

Violating these rules can cause damage to the sensors and changes in the operation of the unit, which cannot be solved by simple cleaning. You will have to change components, which is quite expensive.

What is an intake manifold

Before eliminating the cause of oil getting into the intake manifold, you need to understand what this part is. This device is responsible for mixing the air flow with fuel. If clear proportions are observed, the engine runs like a clock. But as soon as the slightest inaccuracy arises, many problems arise.

When the pistons move in the device, a vacuum is formed. It allows you to achieve intrasystem pressure, which is lower than atmospheric pressure. Naturally, vacuum plays the main role in this process. It is he who is the source of driving force. Thanks to it, auxiliary systems begin to function, which include:

• vacuum operated brake booster;
• a system that controls the amount of harmful emissions;
• a device that corrects the advance angle;
• crankcase ventilation;
• Cruise control.

Of course, this list is far from complete, since much depends on the car make and model.

Signs that oil is getting into the intake manifold

Before you say that there is oil in the intake manifold, you must be absolutely sure that this is the reason for the unstable operation. There are a number of signs that clearly indicate this defect:

• Unusual color of exhaust gases. When oil enters the intake manifold, the smoke from the pipe becomes black or bluish.
• When this defect occurs, the motor increasingly overheats. Moreover, it is not related to the load.
• Thrust drops greatly.
• Fuel and oil consumption increases significantly.
• The motor starts to run too noisy.

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If during operation you detect any of these signs, then you need to check whether oil into the intake manifold. Only after a more detailed diagnosis will you be able to confidently say what’s wrong.

Why you need to clean the intake: diesel and frequent problems due to soot

Owners of cars with a diesel engine are well aware that any malfunctions and deviations in the operation of this type of internal combustion engine require immediate diagnosis and elimination. The fact is that even short-term operation of a diesel engine that has begun to bleed, smoke, etc. can soon lead to much more serious consequences.

Taking into account the fact that repairing a diesel engine is more difficult than a gasoline engine, and many spare parts are significantly more expensive, it becomes clear that during operation it is necessary to regularly check the injection pump and injectors, as well as carry out preventive diagnostics of other expensive elements (for example, a turbocharger).

However, even if certain malfunctions suddenly become noticeable (thrust is lost, speed jumps appear, black thick smoke comes out when changing the gas, etc.), such signs do not always indicate that complex and expensive repairs are necessarily necessary. In other words, the owner should not get upset right away, since the solution to the problem may turn out to be very simple.

The fact is that in many cases, the culprit of diesel engine malfunctions is banal dirt and deposits that accumulate in the intake tract. In this case, the diesel engine behaves as if the unit has reached critical wear.

• As for the reasons for intake contamination themselves, there are quite a lot of them. In the CIS, the culprit can usually be considered to be low quality diesel fuel, low cetane number, and the presence of additional impurities. As a result, all conditions are created for increased carbon formation and coking.
• Also, do not forget that to reduce exhaust toxicity, all modern diesel engines have an EGR system, that is, there is a special EGR valve in the intake manifold, which allows for exhaust gas recirculation.

In short, when the engine is running under light load, this valve allows some of the exhaust to enter the intake and mix with the air that is supplied to the cylinders. As a percentage, about 15% of the exhaust gases make up a share of the total mass of the fuel-air charge.

Due to the fact that there is no oxygen in the exhaust added in this way, the combustion rate of the fuel-air mixture slows down, as a result of which the combustion temperature also decreases. This leads to a decrease in nitrogen oxides (NOx) in the exhaust gases.

In addition to environmental objectives, the recirculation system also reduces the risk of detonation in those modes when the diesel engine operates at extremely lean mixtures. The USR system is turned off (the valve for supplying the exhaust to the intake is closed) occurs when the engine is under high or constant loads, that is, an exclusively “rich” power mixture is needed.

In practice, the engine does not operate often in such modes, especially in the urban cycle. It turns out that the constant supply of exhaust to the intake occurs very often and leads to the fact that a lot of soot settles in the intake manifold, which accumulates on the walls. Thus, contamination of the intake tract in a diesel engine is inevitable and the owner needs to be prepared for this.

Let us also add that the breather of the crankcase ventilation system, which also discharges excess crankcase gases into the intake, is also involved in additional contamination of the intake manifold. As you know, there is oil mist in the crankcase, and oil traps are not completely capable of retaining all lubricant particles.

It turns out that not just soot accumulates in the intake, but oily dirt, which actively contaminates all surfaces and the EGR exhaust gas recirculation valve itself.

It is important to understand that if the valve begins to “hang” or jam, exhaust gases can be constantly supplied to the intake manifold, that is, this will happen in all modes. Naturally, in such a situation one should not expect traction from the engine, but acceleration dynamics from a diesel car.

Let's move on. Having highlighted the USR system and crankcase ventilation among the common causes of contamination of the intake tract of a diesel engine, it is also worth adding faulty glow plugs. The fact is that if the spark plugs do not work correctly, then starting a cold diesel engine becomes very difficult. Diesel fuel begins to enter the intake manifold, which further pollutes the intake.

Taking into account the above, it becomes quite obvious that over time the intake manifold becomes covered with a dense oily layer of dirt, as a result of which the diesel engine begins to operate unstably, loses power, produces smoky exhaust, etc.

Deformation of the cylinder head and its components

Another reason is a faulty cylinder head.

. In this case, some parts of this engine element simply do not fit together tightly, and as a result, oil passes into the manifold. This problem is often accompanied by a white coating in the oil and a decrease in engine power. Thus, it is simply impossible not to notice the malfunction.

There are several reasons for this phenomenon. First of all, the engine overheats. If the power unit is overheated for any reason, then the cylinder head is probably deformed. In this case, she suffers first of all. Therefore, you should operate the motor very carefully, avoiding overheating.

Cylinder head deformation can be determined visually or on a special stand. Carefully inspect the engine; if there is damage, you may notice a loose fit to the mating parts. But, sometimes the problem cannot be determined visually.

The main sign of deterioration of the guides is the knocking of valves

. Moreover, it is impossible to remove the problem by adjustment. Any of these malfunctions will require replacement of the cylinder head.

Ways to increase throttle life

At the manufacturing plant, even at the production stage, the throttle valve wells are coated with a special molybdenum coating. If not carefully cleaned or during use, it can wear out and become damaged. But this is not a death sentence - such coverage can be restored.

For these purposes, special materials based on molybdenum disulfide are used - antifriction solid lubricant coatings, which are produced both in liquid form and in aerosol packaging.

The MODENGY line of materials includes a special composition - MODENGY anti-friction solid lubricant coating for internal combustion engine parts. It is used to restore the factory coating on throttle valves, as well as to protect other engine elements: piston skirts, splines, plain bearings, threaded connections, etc.

This material is applied by spraying from an aerosol can from a distance of 15-20 cm. A distinctive feature of the coating is the ability to cure at room temperature. ATSP can be applied in several layers with intermediate drying for 20 minutes.

The coating kit includes the MODENGY Special Cleaner-Activator. This is a finishing agent that removes remaining contaminants from surfaces and ensures the best adhesion of ATSP to the base of the parts. This material can also be purchased separately from the coating.

Diagnostics

First, let's figure out how to detect oil getting into the manifold. In practice, there are several signs by which the problem can be identified. Knowing all these signs, you are guaranteed to be able to determine the presence of a malfunction:

Cylinder head diagnostics

Deformations can be detected using special stands or visually. It is recommended to carefully inspect the motor for damage. If there are problems, then a loose fit of the parts to each other will be noticeable. But in most cases, visual diagnosis can be difficult. Then it’s a direct road to a specialized stand.

The wear in the valve guides can be determined by the knocking of the valves that accompanies engine operation. By eliminating these causes, you can solve the problem of oil in the intake manifold.

The intake manifold is secured to the power unit using gaskets. This avoids possible air leaks. The gasket also helps limit oil from entering the manifold. But over time it can become damaged. In this case, the oil still gets there.

There can be many reasons for its damage. Most often, these elements fail due to wear and tear. Sometimes the gasket breaks due to overheating. However, modern elements can withstand high-temperature influences. Sometimes the gasket is damaged during engine assembly.

In this case, getting rid of oil in the intake manifold is simple - you just need to replace the gasket. Then the collector is installed back. But you need to observe some nuances. It is recommended to thoroughly clean the surfaces of the engine and manifold. The nuts are pulled with a strictly defined torque.

Before we talk about why the turbine drives oil into the intake manifold, it is necessary to remember its structure.

To put it exaggeratedly, the compressor has a primitive design. It consists of a shaft on which two combs with blades are installed. One of the combs is driven by exhaust gases. The other rotates due to the fact that it is on the same shaft.

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The number of revolutions can be high, so the shaft must be equipped with high-quality bearings. But as practice shows, dry bearings are not able to withstand work in a turbine. The part becomes very hot, as a result the unit overheats and jams.

For the unit to work effectively, it was necessary to somehow remove excess temperature and improve sliding. Oil does this very well. There are two lubrication channels connected to the shaft for each bearing. This way you can get high speeds and high performance.

Everything is fine, but this design provoked the emergence of many problems that cannot be solved today. And the most difficult of them is related to the fact that the turbine throws oil into the intake manifold.

Air filter dirty

Complicated air intake for the turbine is one of the causes of the malfunction. The air filter is often to blame for this - people forget to change it. The air intake pipes may also be partially blocked. It may get pinched or break.

During turbine operation, a vacuum is generated. If there is not enough air, the pressure increases significantly, oil is drawn out of the turbocharger.

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For a turbine, the air filter is very important. Basically, the lubricant is driven away due to the fact that the pressure is broken precisely because of the clogged filter. On turbocharged engines, the cleaning element must be changed every 8 thousand kilometers.

Pipes

This is another reason. If the oil has not been changed for a long time, the pipes tend to become clogged. Even if the turbine is repaired, the pipes are cleaned. It is very important. If the oil is under the intake manifold, then a pressure difference occurs due to the pipes or filter. It is also important to monitor the tightness of the air elements; if the pipes have cracks or other signs of deformation, they should be replaced with new ones.

Otherwise there will be excessive air leaks. This is harmful for both turbocharged and naturally aspirated engines. The problem is further aggravated by the fact that unpurified, dirty air gets through these cracks, bypassing the filter. And the presence of dust in the cylinders of internal combustion engines leads to premature wear of the piston group.

Breather and filter contamination

Everyone knows that the engine has a crankcase ventilation system. It allows you to relieve excess pressure in the crankcase, removing excess gas. It is worth understanding the technical features of this structural element to make it clearer where the oil in the manifold comes from.

Excess gases come out through the engine breather, but they contain a suspension of oil droplets that are knocked out of the “bath” during crankshaft operation. To avoid problems, a special filter is built into the breather, which traps drops of lubricant and returns it to the crankcase.

But, over time, the filter becomes clogged, and then gases begin to flow past this filter. In this case, gases along with oil enter the air filter housing. If the quantity is small, there is nothing wrong with this, but if the problem worsens, the lubricant will leak into the manifold.

What to do in this case? In fact, this problem is quite serious. If you do not pay attention to it in a timely manner, this may result in the need for a major overhaul of the power unit. Therefore, be sure to troubleshoot the problem.

To do this you will need to change the breather

. On some car models, it is possible to replace only the engine ventilation system filter itself. After this, do not forget to change the air filter. After completing this task, the problem with lubrication in the manifold will be eliminated.

Crankcase ventilation

The crankcase ventilation system is designed to reduce pressure in the crankcase. Pressure is formed there due to exhaust gases entering during engine operation. To do this, the crankcase is connected through a pipe to a low pressure zone or a vacuum zone. In naturally aspirated internal combustion engines, this is precisely the intake manifold. If the engine is turbocharged, then the crankcase ventilation is connected to the inlet pipe on the turbocharger.

Any turbine has a line designed to drain oil. It connects to the engine lubrication system. Most often, this line is connected below the oil level in the crankcase. Therefore, when the pressure increases, the oil from the turbocharger cannot be removed normally. This problem may also be due to a clogged separator. This is one of the nodes in the ventilation system. The pipe may also be coked.

How to remove oil from the manifold?

Oil in the manifold is a consequence of component failures and must be removed. The collector must be cleaned. In general, you need to clean it periodically as part of prevention - this will extend its life.

We begin the procedure by placing the machine on a lift. We blow out the power unit with compressed air. It would be a good idea to clean the outside of the engine - this will prevent dust from getting inside the internal combustion engine. Usually the collector is secured with a powerful screw, since the mechanism must withstand large mechanical loads. The immediate place of attachment of the unit is the frame. Unscrew the screw.

Then remove the throttle valve. You will also have to remove all sensors and pipes. To disable the sensors, disconnect the chips. The tubes are usually secured with clamps. To disconnect the manifold from the engine, unscrew the mounting bolts.

We dismantle and disassemble the device. To separate the parts of the manifold, you will have to unscrew a few more bolts. Then we remove the gasket between the two halves - if it is not damaged, it can be used again.

We place both halves of the device in the washing solution and keep it in it for some time. Then we clean them with a brush. We blow the entire structure with strong air pressure (this will remove small particles). We treat the contact surfaces with sealant, then assemble the device.

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If oil smudges are visible on the internal combustion engine, this is a sign of incorrect engine operation. It is advisable to eliminate the causes of leaks without delay. If your existing knowledge is not enough, it is better to contact a car service center for the help of professional technicians.

How to solve the problem permanently

In fact, despite the serious consequences associated with oil getting into the intake manifold, fixing the problem is quite simple. It is enough to install the sensor. This device will monitor the area between the filter and the turbocharger.

If you do not want to spend money on installing a sensor, you can simply follow the manufacturer’s recommendations and change the filter on a schedule. But it is worth making one important note. The rate of contamination depends on operating conditions and loads, so it is not always possible to rely on manufacturers’ manuals.

The intake manifold is an extremely important part. The presence of foreign substances in it leads to disruption of engine stability. Therefore, it is extremely important to monitor the condition of the turbocharger air filter and replace it on time.

How can you tell if there is oil in the manifold?

The working fluid in this unit may not be noticed, since this is a closed area. And yet there are signs of the presence of oil, and usually they are as follows:

1. Traces of working fluid appear in the throttle valve or air filter.
2. Plumes of bluish smoke with an unpleasant odor pour out of the exhaust.
3. The engine begins to intensively “eat” oil. It can disappear in the collector. Therefore, you should always monitor the level of the working fluid.
4. The power of the power unit decreases.
5. Fuel consumption begins to break all imaginable records.

Poor exhaust gas removal

As a result of increased resistance in the exhaust system (damage or failure of the muffler can, contamination of the catalyst, etc.), the pressure in the “hot” turbine scroll increases, causing exhaust gases to enter the middle turbine housing. There, accordingly, the pressure also begins to increase, which leads to the release of oil from the turbocharger.

As you can see, the presence of any of these signs will lead to the fact that even a perfectly operating turbine will begin to throw out oil. First of all, if you find oil in the intake manifold or turbocharger, make sure that the crankcase ventilation system is working properly.

Turbine

Another reason is a turbine malfunction. This structural element constantly circulates oil, which performs the function of lubrication and cooling. The turbine is located near the manifold, its task is to pump additional air, and it is due to this that it is possible to achieve an increase in engine power.

If there are problems with gaskets and seals, oil begins to enter the manifold during turbine operation. Moreover, this happens actively; there is quite a lot of oil. As a result, lubricant begins to spill through the top of the manifold. Actually, this malfunction manifests itself quite clearly.

You can see how the oil is driven through the manifold, and the lubricant also appears on the spark plugs. Having seen this, you can safely remove and repair the turbine. Also, in the presence of such a malfunction, you may notice some dips when gaining speed, this affects the poor performance of the turbine.

Repair in this case will have its own characteristics depending on the car model. For some car models you can find repair kits for turbines. This will allow you to avoid unnecessary costs and quickly repair the unit; you can do this work, including yourself.

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So, we found out how to check the turbine in different ways. If problems arise, do not hesitate to resolve them. After all, not only the compressor, but also the engine itself is subject to increased wear. Do not use additives that say turbine. They will in no way restore the factory clearances, much less return the cracked impeller blades to their previous condition. All these problems can be solved only through mechanical intervention, with removal and troubleshooting.

1. sniff the oil dipstick - you may smell gasoline;
2. leave a drop of oil on the paper; if it contains gasoline, you will see characteristic circles of stains;
3. the “with a spark” method - set fire to warm oil, bring it to a boiling point to cause active evaporation of gasoline.

The reasons for gasoline getting into the oil depend on the characteristics of the internal combustion engine. But in any engine, fuel first enters the crankcase from the combustion chamber with the help of piston rings. If we pour gasoline into the cylinders of a new engine, it will eventually end up in the oil.

Why is this happening? The fuel eliminates the oil film and overcomes leaks where the piston rings are located.

Speaking of a carburetor engine, the most common reason for mixing fuel and lubricant is damage to the fuel pump. This can also include improper operation of the needle valve or overflow of gasoline into the carburetor.

Let's summarize what has been said, the main causes of such problems are breakdowns in the fuel system, ignition system and, of course, in the operation of the engine itself:

№Useful information

Since carburetor engines have a mechanical fuel pump installed, gasoline that gets into the carburetor when the pump diaphragm is damaged can get into the rod channel, that is, into the lubrication system.

If the damage is minor, the problem is hidden, but if the gaps are large, gasoline does not reach the carburetor, the car begins to twitch and is difficult to start.

The solution to the problem will include replacing damaged parts of the fuel pump and oil.

You should not use the car until the identified breakdowns are repaired in order to avoid significant repair costs, which may increase.

As already mentioned, a very common situation is when the problem of gasoline getting into the oil is long-term in nature and occurs almost “asymptomatically”. Can you imagine, the pressure in the lubrication system drops sharply, the emergency oil pressure indicator lights up, the car jerks, roars, but does not drive?

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General recommendations in this situation will be as follows, depending on the breakdown:

1. ignition system repair;
2. fuel pump repair;
3. Troubleshooting the piston system;
4. carburetor or injector repair;
5. mandatory oil change;
6. changing the fuel used (often it is low-quality fuel that damages the car).