Details Created 08.10.2013 14:35
If you have the feeling that the traction in the car has disappeared, most likely the turbocharger has become faulty.
Also, the reason for checking the turbocharger for breakdowns may be a foreign whistle emanating from the turbine. Of course, many experienced car enthusiasts prefer to do the check themselves, but it is still recommended to use the services of professionals.
How is a turbine checked?
In specialized service centers, in order to determine a turbine breakdown, a scanner is connected to a specially designed connector. The reason for turning off the turbocharging may be the charge air pressure sensor or the turbine exhausting its resource. In order to determine the pressure of the turbine, it is necessary to connect a special device with a pressure gauge to its output. After receiving the indicators, it will be possible to accurately determine the need to replace the turbocharger or repair the turbine.
Causes of diesel engine turbine failure
The cause of a diesel turbine malfunction is the emission of blue exhaust smoke during acceleration of the car, and at constant speed it disappears. In turn, this occurs due to the combustion of oil in the engine cylinders, which gets there due to a leak in the turbocharger.
Also, a signal of a faulty turbocharger control system will be black smoke, which appears during the combustion of an enriched mixture due to an air leak in the injection lines.
In turn, white exhaust gases indicate that the turbocharger oil return line is clogged. Another reason may be coking of the turbocharger housing. The acceleration dynamics of a car can become significantly worse due to a lack of air supply from a faulty turbocharger.
Diesel turbine whistling
If you hear a constant noise, whistle or howl while the engine is running, this may be due to an air leak at the junction of the motor inlet and the compressor. If you hear a grinding noise or see cracks and damage to the turbine housing, get ready for the fact that the turbocharger will soon stop working altogether.
Warning!
Most modern machines have automation systems that can immediately turn off the turbine if a malfunction is detected in at least one of the system components. And this, of course, will affect the ability to develop maximum engine power.
Many modern cars are often equipped with a special turbocharger. With its help, you can significantly increase power, as well as other characteristics of insufficiently powerful or volume engines.
Unpleasant whistle in the turbine
During operation of the turbine, a large amount of air passes through it. This applies to all models of turbines, which can be installed on a wide variety of car models. It is important to note that the air passing through the turbine is mixed with fuel. As a result, the total weight of the mixture becomes much greater. Oxygen then runs out under high pressure, and an unpleasant whistle may be heard from under the hood. Moreover, this whistle can occur both at idle and while the car is moving.
What is the reason for such an unpleasant sound? It's all about breaking the tightness of the system. This is why problems arise.
It is important to note that these sounds can alert anyone, because in some cases we are talking about a very loud and shrill whistle. Don’t panic and immediately after you hear the first whistle, go to the nearest service center. You can cope with the solution to this problem on your own. To do this, you need to try to check the air pipe located in the engine as soon as possible. It needs to be checked for leaks. In some situations, the sweetness that comes from the turbine appears on the diesel engine immediately during acceleration. There may also be excess air leakage. In this case, it will be enough just to change all the seals, as well as tighten the fasteners and clamps more tightly. In this case, solving the problem will be much easier.
If you find that the pipes are in too poor condition, it is recommended to replace them with new ones. It is unlikely that they will be repaired. Moreover, you should not try to install pipes that have already been used by someone else.
If the system is sealed, but the whistle is still heard, you need to carry out a much more in-depth diagnosis. You need to understand that the turbine is an extremely important technical element. It should work as stably as possible. Also, do not worry about a short and light whistle. This is common. However, if the device simply roars, you need to get it repaired as soon as possible.
What are the causes of whistling?
Typically, a whistle from the turbine is a sign of depressurization of connections in the system. In addition, the turbine can also whistle due to the passage of compressed air through various cracks. In this case, you can deal with the problem on your own. In order to do this, you need to find the very place that is the main cause of the noise (whistle). This can be done extremely quickly.
Modern cars are often equipped with a turbocharger - this can significantly increase the power and performance of even low-power and low-volume engines. As you know, no engine can operate normally without a certain amount of air. To burn one liter of fuel in combustion chambers, you need at least 11 thousand liters of oxygen. But in order for air to fall into the cylinders, it must pass through the filters, the intake manifold, bypass the throttle valve and then enter the gap in the seat and the valve itself. The engine's need for air is never fully satisfied. A turbocharger accelerates the air and forces it into the combustion chambers. During operation, the turbine may make sounds. This worries many car owners. Let's find out how this unit works, whether the whistling of a diesel turbine during acceleration is dangerous, and what it means.
About creating a turbine
Most car owners are seriously convinced that turbo engines are a relatively recent invention. It is believed that they appeared in the second half of the 20th century, when almost all models of the German automobile industry were equipped with turbochargers. But it is not so.
The date of birth of the turbo engine is considered to be 1911. It was then that the American engineer Alfred Buchi managed to obtain a patent for the industrial production of a device that could increase the power and technical characteristics of conventional motors several times.
But for all the efficiency of these first turbines, they were bulky and increased the weight of the engine many times over. The development of turbocharging for passenger cars has stopped, but turbines have been used very actively in freight transport. In the United States, automakers were in no hurry to industrially install a supercharging system. Then (as well as now) the emphasis was on volumetric atmospheric power units. There is even a saying “nothing can replace volume.”
In Europe, fuel was treated more economically than in the United States. In addition, in the 20th century, Europe experienced a fuel crisis. Automakers began to reduce engine sizes while increasing power. The boost system helped with this. The technology has improved, structural elements have become lighter. However, among the disadvantages was still high fuel consumption - turbocharging did not find popularity among ordinary car owners.
Element in a diesel engine
As you know, the diesel engine was developed in 1893. Over time, its design was refined, many parts were subjected to repeated changes and modifications. Engineers worked on ways to supply the fuel mixture, as well as on its balance itself. Then the engineers developed a turbine designed to increase the productivity and performance of the unit due to more complete combustion of fuel in the cylinders. This process is based on air compression in the internal system - this made it possible to increase the density of the supplied air. This way the mixture burned completely, and less harmful emissions were released into the atmosphere.
There are low pressure and high pressure turbines. High boost devices are more efficient and also have a more complex design.
Design
A modern turbocharger is a device consisting of the following components. These are two casings, each of which is equipped with a compressor and a turbine. These casings are made of heat-resistant cast iron alloys. The turbine is equipped with a special wheel - it is also resistant to high temperatures.
Operating principle of a turbocharger
The operating algorithm is as follows. The combustion products that are discharged from the exhaust manifold go to the intake pipe of the turbocharger. Then they pass through the turbine housing - the channel in the housing has a variable cross-section. As the exhaust gases move through the channel, they increase their speed and act on the turbine wheel - under this influence it rotates. The number of revolutions of the turbine rotor depends on many factors. The average rotation speed is 1500 rpm.
The outside air, passing through the air filters, is thoroughly cleaned of impurities and enters the intake manifold in compressed form. Then the channel closes. The mixture is further compressed and ignited. Next, the exhaust manifold opens. An intercooler is installed at the entrance to the combustion chambers.
It is necessary to cool the hot air coming from the turbocharger. This increases the density and decreases the volume of oxygen. More air enters the cylinder, which, after mixing with fuel, will burn more efficiently. Due to this, power increases significantly and fuel consumption decreases.
If the turbine whistled
During operation, a huge amount of air passes through it, which then mixes with fuel, increasing the weight of the mixture. Oxygen is pumped under high pressure - there may be a whistle under the hood both at idle and when driving. One of the reasons is a violation of the tightness of the system.
These sounds can be alarming. But you shouldn’t immediately go to a service station for diagnostics. You can try to fix the problem yourself. First of all, experts recommend checking each air pipe in the engine for leaks. Often, when a diesel turbine whistles during acceleration, there is excess air leakage. To fix the problem, it is enough to replace the seals, tighten the clamps and fasteners.
If the pipes are worn out, they are replaced with new ones. They cannot be repaired, and it is not recommended to install used ones.
If the system is sealed and the whistle is still heard, then it is necessary to carry out a more in-depth diagnosis, because the turbine is a very important technical element that must operate stably. Many people don’t know, but a slight whistle from a diesel turbine during acceleration is a common occurrence. But if the device roars, then this is already associated with problems.
How does the turbine whistle?
Often, compressors make these sounds when they gain speed in the range from 1.5 to 2.5 thousand revolutions. It doesn’t matter how quickly you start accelerating. The whistling will still occur. The sounds do not stop even if the rpm drops. In this case, the engine characteristics do not change in any way. It's just that the amount of air passing through the turbocharger passes through special holes that have lost their shape over time. As a result, the driver hears a nasty whistling of air from the engine compartment during acceleration.
Light whistling sounds can be observed even on new turbines. But it goes away quickly. And after a while, if the device is working properly, only the sounds of the motor are heard. If the turbine whistles and the speed drops, you should replace the hose that connects it to the intercooler. Sometimes the air heat exchanger itself may be to blame. If a whistle appears during acceleration, similar to a broken intercooler, you need to carry out an inspection - it is easier to repair it than a turbine. The part can be soldered or, in case of serious malfunctions, replaced with a new one.
Why is the intercooler leaking? The fact is that the element is installed in the front of the car. Not only is it located in front of the radiator, but it is also fixed almost at the bottom of the bumper. Therefore, various stones can get here.
This is one of the main reasons why a diesel turbine whistle occurs during acceleration. By the way, the intercooler is not installed on all turbocharged engines. This must be taken into account when diagnosing. In some cases, the compressor is oil cooled (for example, on the Kammniz diesel engine of GAZelle-Business).
Reasons for whistling
The number of revolutions at which a fully operational turbine impeller rotates is more than ten thousand per minute. Definitely, the whistle of a diesel turbine during acceleration is a sign of depressurization in the system connections. The turbine whistles due to the passage of compressed air through the cracks. You can fix these problems yourself. To do this, you need to find the place that is the cause of these sounds.
Also, a turbine whistle when accelerating can occur due to the passage of air anywhere from the intake manifold to the intercooler. Also, the sound will occur if there are gaps between the cylinder head and the intake manifold (loose fit of the block surfaces). If the gasket is broken, then this is also one of the reasons for the whistle. Sound may also occur if foreign objects get inside the mechanism.
Other signs of trouble
Not only a whistle during acceleration can indicate a unit malfunction. There are other signs as well. These can be used to determine that the turbine needs repair. We will look at typical unit malfunctions based on the color of the exhaust.
Blue smoke
This is the first and most characteristic sign of a breakdown. When accelerating, blue smoke will be emitted from the exhaust pipe. Moreover, if the engine operates at lower speeds, it will not occur. The reason is the burning oil that gets into the engine cylinders due to leaks from the turbocharger. A characteristic whistle may also be heard when accelerating.
Black smoke
Smoke of this color indicates that there is a fire in the cylinders due to an air leak in the charge lines or in the intercooler. Also another reason is the electronic control system. It may malfunction. Additionally, inspect the condition of the injectors.
White smoke
The reason for the formation of such smoke must be sought in blockages in the turbine oil drain line. If oil leaks are found on the unit body or there is oil on the air path pipes, this is caused by a clogged system in the air supply channel. The turbine axis could also become coked. As a result, gases of an unnatural color come out of the exhaust.
Conclusion
We looked at why a diesel turbine whistle occurs during acceleration and the reasons for the appearance of these sounds. In most cases they are associated with air leaks. You can eliminate depressurization yourself. But if the breakdown is more serious, then you can’t handle it on your own. Modern turbines have a complex design, and repairs are best left to professionals. They are able to determine by the sound what the turbine is whistling about.
Owners of cars with turbocharged engines are often faced with a situation where a whistle appears when the supercharger is operating, some of them do not attach much importance to this phenomenon, believing that this is how it should be, others begin to seriously worry why the turbine is whistling, how much money will have to be invested in its repair.
Should I immediately panic, is the whistling of the turbine a sign of its breakdown? Let's try to figure it out and answer this question in more detail. First of all, you need to pay attention to the nature of the whistle and determine the place from where it is heard, then most likely the reason will be clear. The operating principle of turbocharging is actually not that complicated; the turbine impeller accelerates the exhaust gases, thereby creating high pressure, which ensures that more fuel mixture enters the engine, resulting in increased power. Where air flows under pressure pass, there is a high probability of a whistle appearing, so it is impossible to immediately and unequivocally say that the appearance of some extraneous sounds during operation of the supercharger is already a sign of a breakdown. Cars with a turbine usually have a rather complex air intake line, is there a whistling sound? Perhaps this air flow is moving from one pipe to another pipe.
If a small whistle appears along with increased mileage, there is nothing particularly terrible about it; perhaps accumulated deposits in the air channels have somewhat changed their cross-section, and the air pressure has increased. In this case, the tone of the whistle will be low, and the whistling sound itself will not be loud, it appears as if from the depths; by the way, this phenomenon is more frequent on supercharged diesel engines than on gasoline engines.
It happens that the whistling of a turbine is indeed a sign of a breakdown; if it is loud enough and its tone is high, you should be wary, there may be problems. You should always listen to the sounds coming from under the hood, and if the whistle is heard not only outside, but also makes itself felt in the cabin, you need to try to determine its source and the reasons why it occurred. First of all, you need to make sure that it is the turbine that is whistling; in any modern car there are quite a lot of units that can make a whistle. If it appears at idle and does not change in character as the speed increases, the turbine most likely has nothing to do with it, but if a whistling sound appears while driving, and especially at the moment of acceleration, it is most likely the cause.
Most often, a whistle appears due to depressurization of the system: air somewhere either escapes under high pressure, or air leaks somewhere. In both cases, depressurization affects engine operation, not always, but often in such situations, fuel consumption increases, while engine power decreases. So-called “plugs” occur during overclocking. This is due to the fact that a non-optimal mixture enters the engine. It is not difficult to determine the location of an air leak if it is located in an obvious place to which access is not limited in any way, but often the opposite happens, the problem is not on the surface, but literally in the depths. If the location of the air leak cannot be determined audibly or visually, you will have to disassemble the entire air path to remove the intake manifold. In order to determine the location of an air leak, you can use the old effective method: apply a soap solution to the suspicious part, bubbles will appear where the air passes through. When checking, special attention should be paid to the air pipes; a small, invisible crack can be the source of the whistle. It is also necessary to check the presence of seals and gaskets and how correctly they are installed, how well the clamps are tightened, the condition of all other fasteners; if necessary, you can replace not only them, but the entire intake manifold completely. This method of solving the problem is especially justified for relatively inexpensive cars with a turbocharged engine, for example, it is easier to buy at an affordable price than to repair a damaged one.
The cause of the whistling may be the turbine itself, or rather its damaged housing or intercooler (if it is included in the design), which, by the way, is less protected from mechanical influences, since it is installed directly behind the radiator grille, while the turbine is further away, it is protected by several components and parts under the hood. The intercooler or, as it is also called, the turbine radiator can be checked without dismantling; to do this, it is enough to supply air to the inlet. Such parts can be repaired, if of course the damage is minor; sometimes for a work van like this it is easier to find a new one than to restore the damaged one.
The simplest and most easily eliminated cause of a turbine whistling may be foreign objects or debris caught in the air duct; at the very early stage of diagnosis during disassembly they will be immediately noticeable
The reason why the turbine whistles is not always the depressurization of the air ducts, mechanical damage to the unit or its individual elements, for example, impellers sometimes also happen, the appearance of play, or simple wear. In such cases, the whistle of the turbine is not the first and only sign of its failure; most often it is confirmed by black smoke from the exhaust pipe. There are other signs:
increased oil consumption;
unstable engine operation, especially noticeable during acceleration.
If suspicions at a car service center are confirmed, expensive repairs cannot be avoided, the damaged unit can be restored, but more often experts recommend replacing it. In most cases, the choice is justified; for example, it will cost the owner a very reasonable amount.
So, is it worth attaching importance to the fact that a whistle suddenly began to be heard from under the hood of a turbocharged car? Considering the above, first of all you need to pay attention to its tone, volume and the situations in which it occurs. If it is not loud and low and appears after a while along with an increase in the car’s mileage, there is most likely no need to worry, everything can be reduced to the peculiarities of the turbine’s operation.
If the whistle is high and loud, and at the same time the engine begins to work unstably, oil consumption has increased, perhaps somewhere, that is, there is a crack or even several, you will have to fix them.
When, in addition to the whistle, there are other alarming signs, for example, black smoke from the exhaust pipe, it is better to immediately contact a car service center.
When the turbine operates, a large amount of air is used, which is mixed with fuel, increasing the mass of the combustible charge. The air is pumped under high pressure to a certain level of density, so any violation of the tightness of the system can lead to a characteristic whistle under the hood.
If the turbine whistles, do not rush to immediately contact the service station. First, check the tightness of all air pipes. In some cases, it is enough to install new seals, tighten the clamps and tighten the fasteners. If the pipes are worn out (cracks, holes, ruptures are observed), they will have to be replaced. Sometimes it can be difficult to detect a malfunction, since some damage can only be seen from the inside.
If you are sure that the turbocharging system is leak-tight, and the whistling does not stop, it is best to contact a specialist. They will make a professional diagnosis and determine the exact cause of the problem. Remember that the turbine is not a robber nightingale, so it should not whistle.
Diesel turbine whistles
If we talk exclusively about diesel engines, turbine whistling is most often associated with a leak or air leak, which circulates in the system with high intensity. When it leaks through a loose connection or mechanical hole, a characteristic whistling sound is observed. In this case, the traction characteristics of the engine may not change at all.
So, a diesel turbine whistles in the following cases:
Leakage of air masses along the compressor-intercooler/intake manifold line;
Suction in the “air filter-compressor” section;
Leak in the gap from the intake manifold to the cylinder head;
Hole in intercooler;
A foreign object has entered the turbine or compressor part.
A slight whistle can also be observed when using a new turbine, but it goes away quite quickly.
