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Diesel intercooler oil: causes and solutions
Diesel intercooler oil: causes and solutions

Now almost every diesel engine is supercharged. This allows you to significantly increase the performance of the motor, which is positively reflected in the dynamic characteristics. However, the pressurization system has a special device. Since air is supplied under pressure, it tends to heat up. Hot air in the intake negatively affects the performance of the internal combustion engine. Therefore, in the design of turbocharged engines, a special radiator for air is provided - an intercooler.

Over the years, the car owner may face an unpleasant situation - oil appears in the intercooler pipe of a diesel engine. The reasons for this phenomenon may be different. From a corny clogged filter to problems with the turbine itself. Today we will look at why oil appears in the intercooler of a diesel engine andhow to fix this problem.

diesel engine

Main reasons

Why does oil form in the pipe or in the radiator? There are several reasons why oil appears in the intercooler of a diesel engine:

  • Incorrect operation of the crankcase ventilation system.
  • Clogged oil or air filter.
  • Duct problems.
  • Engine overheating.
  • Malfunctions of the turbine itself (in this case, the stuffing box).
  • Turbocharger oil line bend.

No car owner is immune from this trouble. Well, let's take a closer look at all these reasons.

Oil in diesel intercooler due to crankcase ventilation system

This system is present on every engine. During hard acceleration, as well as under load, the combustible mixture creates more pressure than usual. Because of this, part of the gases will break through the compression rings. As a result, the pressure in the crankcase increases.

oil in diesel intercooler

To compensate for this difference and prevent oil from being squeezed out of seals and gaskets, a gas ventilation system was invented. On a serviceable car, they pass through the intercooler, and then enter the cylinders, where they burn out along with the fuel. But over time, the system performs worse. The valve spring loses its elasticity, and the oil separator no longer copes with its task. As a result, the pressure in the crankcase increases. This causes oil particles to enter theradiator. This problem is dangerous in that it can lead to punching of the seals. As a result, the oil level drops rapidly. But the motor does not eat oil - it is simply squeezed out through poor-quality seals.

Lubricity will also decrease, the engine is threatened with oil starvation. And this entails the appearance of burrs on the shaft. Among the characteristic signs of problems with the crankcase ventilation system, it is worth highlighting:

  • Loss of engine power.
  • Increased fuel consumption.

If the problem is not corrected in time, part of the oil will enter the combustion chamber. Because of this, the combustion mode of the fuel will change.

Oil filter

We continue to consider the question of why there is oil in the intercooler of a diesel engine. There are many reasons, as you know, but one of the most commonplace is a clogged oil filter. Because of this, the circulation of the lubricant may worsen, while the pressure increases. As a result, oil seals are forced through in the internal combustion engine, and the turbine drives oil drops into the intercooler of the diesel engine. Yes, the filter has a bypass valve. But, unfortunately, it does not work on all models. Poor quality filters are not able to bypass the lubricant, as a result of which the pressure increases. If you install a new cleaning element, the problem will not be completely solved. It is necessary to change the squeezed-out seals. Only in this way will the oil stop flowing.

oil in engine intercooler causes

Air filter

This is another reason why there is oil in the diesel intercooler. According to the regulations, the filter shouldchange every 20-30 thousand kilometers. However, there is one amendment. If the car is operated in extreme conditions, this interval must be reduced by 2 times. Frost is not one of these conditions. This is riding in a dusty area.

When the intake stroke occurs, the piston goes down, creating a large vacuum in the crankcase ventilation system. If the filter becomes clogged, due to the pressure difference in the ventilation system and the intake pipe, oil will enter the intercooler. In addition, due to lack of air, the engine will run worse. Consumption will increase and power will decrease.

The solution to the problem is very simple. If the air filter is clogged, it must be replaced with a new one. It is not too expensive, and therefore there is no need to hesitate to replace it.

Duct problems

During operation, mechanical damage to the air duct is possible. It may be a crack that is invisible at first glance. As a result of even a small amount of damage, the turbine will throw oil into the intercooler. And this happens due to a violation of the tightness in the intake. As a result, a vacuum zone is formed, which draws in engine oil. The pipe can be repaired, but it is not a fact that soon such a crack will not appear in a neighboring place. Therefore, it is better to replace this element with a new one.

Engine overheating

In case of prolonged operation under load or due to a malfunction of the cooling system, there is a risk of engine boiling. As a result, not only the volume of crankcase gases increases, but the oil also evaporates strongly. When antifreeze boils in the block heada vapor lock is formed. The temperature of the head increases greatly, and this leads to intensive evaporation of the oil. In addition, it becomes more liquid, due to which part of the lubricant flows freely through the seals. As a result, the turbine drives air with drops of oil. This changes the mode of operation of the engine and adversely affects its performance.

Damage of turbocharger oil seal

Any compressor has its own life limit. Unlike gasoline engines, the turbine runs longer on diesel engines. The first troubles arise on runs over 200 thousand kilometers (with the exception of commercial vehicles). Over time, the gland ceases to cope with its task. As a result, oil particles enter the intake manifold, passing through the intercooler. By the way, the latter will initially catch part of the lubricant. But as soon as its level reaches the lower cells, carburetion will occur, due to which the air flow will drag oil drops along with it. As a result, the lubricant burns out along with the fuel. Classic symptoms occur - the car does not drive and consumes more diesel than it should.

in the intercooler of a diesel engine causes

Oil return line bend

As you know, the turbine needs lubrication. However, the oil circulates here constantly, unlike bearings. Therefore, the design provides a branch pipe for draining oil. And if this element is bent, the removal of lubricant will be difficult. As a result, the turbine will drive oil into the intake. To fix this problem, you only need to align the elbow orreplace it if damaged.

Consequences of having oil in the intercooler of a diesel engine

First of all, all used diesel vehicles have a small amount of oil in the intercooler. Usually its volume does not exceed 30-50 grams. This is due to the high pressure that occurs during the combustion of fuel. As long as the lubricant is below the radiator cooling cells, the motor will run without problems. However, when the level is higher, the phenomenon that we talked about above will occur - carburetion.

diesel engine oil causes

The oil that enters the chamber does not have time to burn out in one cycle, and therefore the product residues burn out in the block head, as well as in the exhaust manifold. What consequences can this lead to? As a result, there is a risk of burnout of the valves and the exhaust manifold. The temperature of the latter can reach 700 degrees Celsius, which is very significant. The temperature of the cylinder block itself also increases. Even a good cooling system can't handle that much heat. Increased risk of engine overheating.

What to do?

If the 2007 Tuareg Diesel intercooler, for example, is clogged with oil, what measures should be taken to solve the problem? First of all, you need to check the condition of the filters. Next, check the operation of the crankcase ventilation system. It is also worth inspecting the turbine seals. If you do not have sufficient diagnostic experience, it is better to entrust this work to specialists.

Flushing the radiator

To eliminate the oil in the intercoolerdiesel engine, the causes of which are discussed above, it is imperative to flush the radiator. This operation can be done by hand. For this you need:

  • Remove the intercooler from the vehicle.
  • Clean the outer surface. This can be done in several ways - with a light brush (or a broom), as well as with a stream of water. But you should be careful. Like any radiator, the intercooler has a very fragile honeycomb. Their hall threatens to worsen the cooling of the air. Therefore, the jet must be directed only perpendicularly. And the water pressure itself should be small. You can try to flush the radiator externally with Karcher, after soaking the intercooler with foam. This is a very efficient way. But since the pressure of the device is high, you need to work at a great distance.
  • Clean the inside surface. To do this, it is necessary to fill in a mixture of gasoline, acetone and kerosene (one to one ratio) and close the exits. In this state, you need to leave the intercooler for a day. Next, you need to drain the mixture.
  • Mix dish soap and hot water. The ratio should be as follows: 10 grams of detergent is added per liter. Then the solution is poured back into the intercooler. However, waiting for such a long time is no longer required. It is enough to leave the radiator for 3-5 minutes. For a better result, you can shake it from side to side. The mixture is then drained. If the water turned out to be very dirty, this washing should be done several more times. And so on until the mixture is clean after washing.
  • Remove detergent residuesolution. To do this, ordinary water is poured into the radiator (but it must be clean). You need to drive the water away until all the soap is gone from the insides.
oil in diesel intercooler causes

There are other ways to flush the oil in a diesel intercooler. To do this, use a carburetor cleaner, diesel fuel and acetone. Some, in order not to perform such complex cleaning regularly, do the following. The bottom of the radiator is drilled and a nut is welded, into which a bolt with a copper washer is screwed (it is copper that is used, since steel will not give such tightness). Once a season, it is enough to unscrew this plug and drain the oil with all the condensate. Yes, unlike flushing with removal, this operation is not as effective. But as we said earlier, if there is little oil in the system, this does not harm the engine at all. Therefore, such periodic cleaning is quite relevant.

Keep your engine oil level

If your diesel car has more than 200,000 miles and has not yet had a turbine repair, it is important to check the engine oil level. Gradually, the turbine will begin to eat it up. And for a heavily loaded engine, a low oil level is especially dangerous.

oil in intercooler

Summing up

So we've looked at why oil can appear in a diesel intercooler. There are plenty of reasons, as you can see. This phenomenon can be provoked by various factors.

If the car began to behave differently, you need to find out where the oil in the diesel intercoolerengine could appear. You need to build on the small, that is, check the filter and oil drain. It is important not to hesitate to eliminate the cause. Otherwise, the oil in the intercooler pipe of a diesel engine can cause the engine to overheat, not to mention the deterioration in performance. Also, on engines with oil in the intercooler, strong deposits form, the valves burn out. And repairing the block head or replacing valves is not only difficult, but also expensive.

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