Exhaust smoke and its colors on an Eos: causes and severity

Exhaust smoke and its colors on an Eos: causes and severity

In a few words:
According to the color of the exhaust smoke that is released from the exhaust pipe of your Eos you will be able to identify the possible causes. The colors of the exhaust smoke that your Eos may produce will help you find the problem. In order of priority from the least to the most dangerous, these colors are: white, blue, black, mix of two colors.

First, it should be said that the exhaust gas that is usually released through the exhaust pipe of your car is basically invisible. You should see a faint and short-lived exhaust that fades shortly after appearing only if you speed up abruptly. If your Eos discharges visible exhaust smoke then it is very likely that you need to take it to a specialist.

White exhaust smoke coming from the exhaust pipe on an Eos

The exhaust gas that comes out without strength and elevates considerably (it may get over the roof) but then fades without any trace when your car is idling may only be water vapor. This exhaust does not smell like anything in particular and it can be seen if the temperature is low or if there is humidity. If this is the case, do not worry.

If the white exhaust smoke does not fade, it is dense and smells, then it is associated with a coolant leak. In this case, the coolant level of your Eos should be low. Have your car checked up by a specialist to confirm this leak and prevent your engine from overheating.

⚠️ Check the recovery tank. If you see that the coolant is bubbling that means that it is leaking into the combustion chamber. This is caused by a leak of exhaust gases into the cooling system. If your car has these symptoms you should have your engine checked by a specialist at once since this malfunction may bring serious problems.

This liquid leak may be caused by the following reasons:

  • The cylinder head gasket is damaged (which is the cheapest problem to fix)
  • The cylinder head or the engine block are cracked (which is more expensive)

Blue exhaust smoke coming from the exhaust pipe on an Eos

At first sight this exhaust smoke seems white but it has a blueish tone, a certain density and a particular smell, like something is burning. Moreover, its volume increases significantly when you step on the accelerator.

This blue exhaust smoke indicates that the lubricant oil is burning, either because there is a leak into the inside of the combustion chamber or a leak into the exhaust system.

⚠️ Check if the level of lubricant oil of your Eos is decreasing drastically to verify if that is the cause.

The causes for this lubricant leak are usually the following:

  • The valve stem seals are in a bad shape
  • The piston rings are worn down
  • Leaks of oil in the supercharger (if the engine of you Eos has this system)

Unfortunately, fixing any of these problems is expensive and they usually affect high mileage engines (with more than 90,000 miles) or cars with badly battered engines.

If the exhaust smoke is blue but it is not too dense, it may be caused by a blockage in the crankcase ventilation system.

⚠️ In this case, the exhaust smoke will come from the engine and not from the exhaust pipe.

It is normal to see blueish exhaust coming from the exhaust pipe of mopeds and motorbikes with a two-stroke engine, and, in those cases, this exhaust is not caused by a failure.

Black exhaust smoke coming from the exhaust pipe on an Eos

This problem is usually seen in diesel engines and it is caused by a great increase in the amount of fuel supplied to the engine, that is to say, the engine is burning more fuel than it should.

⚠️ Check if the consumption of fuel of your Eos has increased significantly. You should also notice this because of the reduction of power of the engine.

You can also verify this flaw by putting a white cloth inside the exhaust pipe, clogging it up for a few seconds. This cloth will turn black instantly due to the expelled coal particles.

This black color is caused by the generation of hydrocarbons that are not completely burnt. They create more carbonaceous particles which soil the lubricant oil and they settle in each nook and cranny of the engine of your Eos. At the same time, they are also accumulated inside the combustion chamber as hard crusts that are abrasive and wear down movable pieces.

The exhaust system is also affected because of the accumulation of cinder, which also poses a threat to the catalytic converter, the particle filter or the muffler of the car.

This problem may be caused by any of the following items:

  • The air filter is too dirty.
  • The fuel injectors, the fuel pressure regulator, the throttle position sensor (TPS), or the Manifold Absolute Pressure (MAP) sensor are dirty or there is an electrical flaw in them.
  • The Exhaust Gas Recirculation (EGR) valve is malfunctioning (this valve recirculates the exhaust gases back to the engine). When you accelerate, this EGR valve remains open so that the exhaust gases can get inside the engine once again.

Two-colored exhaust smoke coming from the exhaust pipe de tu Eos

In the worst case scenario the released exhaust will be two-colored. This means that there are many simultaneous causes for this problem and it is important that a specialist investigates this as soon as possible to prevent further failures.

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Volkswagen Eos problems: Exhaust smoke colors


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