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Oil In Intercooler Pipe

Oil In Intercooler Pipe: Causes & How To Fix

If you have a basic knowledge of car parts, then you must have heard of the intercooler. It is the system that cools the intake air and helps increase the efficiency of the engine.

However, if there is oil in intercooler pipe, it will significantly affect the performance and life of the machine. This article will analyze the causes, signs, and solutions to the problem of oil leaking into the intercooler system.

What Is An Intercooler?

The intercooler is a part that cools the intake airflow into the engine. It is usually available in vehicles using superchargers or turbocharger turbochargers.

Turbocharger helps compress air from the outside to increase the amount of air injected into the cylinder, and the engine can burn more fuel. However, this compression will increase the temperature of the gas stream.

Therefore the amount of oxygen in the gas stream will be low because the oxygen concentration is inversely proportional to the air temperature (ie, the higher the temperature, the lower the oxygen concentration, and vice versa). Since then, the combustion efficiency of the engine is also not high.

So they need an intercooler system to cool the air stream after compression.

How Does The Intercooler System Work?

How Does The Intercooler System Work

The airstream, after compression by a turbocharger or supercharger, will have a high temperature.

Depending on the cooling system, this compressed air will pass through the intercooler and be cooled by air or water. The air coming out of the intercooler will have a low temperature. It helps to take in more oxygen and increase the amount of fuel burned in each cylinder.

Furthermore, it also increases engine stability by ensuring that the air-to-fuel ratio in each cylinder is at a safe level.

In addition, the intercooler system also brings many other benefits to the vehicle, such as smooth engine sound and limited environmental pollution due to completely burned fuel.

However, if you let oil leak into the cooling pipe system, it will hinder the work of the intercooler and the engine. It results in reduced performance and engine life due to reduced cooling efficiency and contaminated intake air.

What Causes Oil To Spill Into The Ducts Of The Cooling System?

Oil In Intercooler Pipe

The intercooler’s design, construction, and operation have nothing to do with oil, so where does the oil leak into the intercooler pipe? Yes, it comes from the turbocharger or supercharger department.

To compress the air, the turbocharger must rotate at up to 280,000 rpm. Therefore it needs oil from engine oil for lubrication to reduce friction.

# Turbo oil seals are worn

After a long time of use, turbo oil seals will wear down and form small holes. Lubricating oil will then flow into the intake air cooling system duct.

Over time, the amount of oil that accumulates at the bottom of the intercooler pipe will gradually increase and reduce cooling efficiency and engine performance.

# Other notable causes

In addition, oil seeping into the cooling pipe also originates from other causes such as:

  • The engine intake air filter is clogged.
  • High oil pressure.
  • Replaced the wrong type of turbocharger
  • There is a problem with the turbo unit.

# Signs To Identify Oil In Intercooler Pipe

If the oil spills in with a small amount, it does not affect the engine much.

However, if the oil accumulates a lot, the engine will be prone to problems. Therefore, you need to know how to detect and fix oil leaking inside the intercooler pipe in a timely manner.

Because the cooling system is located deep inside the car, you have to rely on the car’s signs to detect its problems.

You can depend on the following symptoms to know if the intercooler has a problem or oil in the intercooler pipe.

# Engine efficiency is reduced.

The first sign that you can easily recognize is that the engine has reduced capacity. Due to insufficient energy from incomplete fuel combustion, your vehicle accelerates very slowly, and it is difficult to achieve the desired speed.

The reason is that the intake air stream after compression by the turbocharger is not cooled, so oxygen is deficient.

As a result, the engine cannot burn fuel efficiently. Moreover, the amount of oil accumulated in the intercooler pipe also interferes with the engine’s air intake path. Over time it will adversely affect your engine.

When the engine is not working correctly, the check engine light will light up. It is also a warning sign for you. But look for other signs to determine if the oil in the intercooler pipe is causing the engine problem?

# Increase fuel consumption.

A second consequence of not effectively cooling the intake air is wasted fuel. It is because the cylinders cannot burn all the energy and do not generate enough power. Therefore the engine needs to pump more fuel to achieve the desired speed.

# Unusual smoke from exhaust.

The oil that accumulates in the intercooler pipe can mix with the intake air and enter the cylinder.

Here, the oil is burned and produces black smoke. So, if there is oil in the intercooler or not, observe the exhaust pipe when the car is running. If it has black smoke coming out, your vehicle has a problem with the oil and cooling system.

How To Clean The Intercooler And Oil Spilled Pipe

If you get 2 to 3 of the above signs, it means that there is oil built up in the intercooler pipe of the cooling system.

The first thing you need to do is find the cause and fix it. If the oil from the turbo oil seals is worn out, you should replace it with a new one. It is by cleaning the oil-filled intercooler tubes.

There are 2 main steps to clean the intercooler pipe: remove the intercooler from the vehicle and wash them with detergents.

# Remove the intercooler from the car

This task is not difficult if you know how to remove it. However, we recommend that you follow the manufacturer’s manual to ensure the safety of people and vehicles.

  • Step 1: Read the instructions for disassembling the intercooler.
    You can use manuals or online video tutorials.
  • Step 2: Disassemble the bumper.
    You can use a screwdriver to tighten the screws that attach the bumper to the car. At this point, the entire intercooler and its pipes will be exposed.
  • Step 3: Disassemble the intercooler from the intercooler pipes.

The intercooler will attach a pipe from the turbocharger and a pipe to the engine. Use a flathead screwdriver to remove and separate the intercooler part. However, when drawing, let the basin catch the oil flowing from the pipes!

# Clean the intercooler with detergent

After disassembling the intercooler, all that remains is to clean it.

  • Step 1: Wear gloves and goggles.
  • Step 2: Pour all the oil in the intercooler into the oil tank.
  • Step 3: Place the intercooler in a large pot or bucket.
  • Step 4: Spray cleaning solution all over the surface of the intercooler.
  • Step 5: Spray cleaning solution into the inside of the intercooler through the 2 mounting holes with 2 hoses.
  • Step 6: Stand the intercooler upright and wait 60 seconds for the excess oil to drain out.
  • Step 7: Submerge the intercooler in kerosene and hold for 15 minutes. If it is not clean, then soak for another 15 minutes in fresh kerosene.
  • Step 8: Let the intercooler dry naturally and reinstall it in the vehicle.


We have just learned in detail about the causes, signs, and how to get rid of oil in the intercooler pipe.

Hopefully, you can detect problems related to oil leaking into the cooling system early through this article.

Besides, you also know how to fix it so as not to affect the car’s engine adversely.

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