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Causes of Car Blowing White Smoke From Exhaust – How to Fix It?

white smoke

It is relatively normal for a car blowing white smoke from exhaust. After all, internal combustion engines produce exhaust gasses that must go somewhere. What comes out of the exhaust is hardly visible. But if there is discoloration, you should take a closer look.

What Causes White Smoke From The Exhaust??  

White smoke from the exhaust indicates that water has entered the engine or the exhaust. The engine’s heat makes this water evaporate, leading to the emission of white smoke. Water penetration can have various reasons, for example, a technical defect. Low temperatures and car washes are also possible causes.

If your car smokes white, it doesn’t have to be defective. Besides, you should take the white smoke seriously and localize the cause. In the event of a technical problem, quick action is essential.

Why A Car Shouldn’t Smoke White 

When the engine is in good condition, the mixture of air and fuel required for combustion is mixed. Under these conditions, combustion in the cylinder occurs under the best possible conditions. The mixing ratio of petrol and air is particularly important.

The fuel-air mixture can only burn completely if this is correct. This is one of the reasons why exhaust gases are almost transparent.

White Smoke From Your Car’s Exhaust – Why You Should Act Quickly 

As already mentioned, almost colorless exhaust gasses come out of the exhaust of a working car. The reverse conclusion suggests that white smoke from the exhaust indicates a technical defect.

If there is a defect, the cause of the white smoke can lead to further problems. Possible issues that can occur if the technical fault is not rectified are, for example:

1. Increased fuel

2. Increased emissions and pollution for people, animals, and plants

3. More extensive technical damage to the vehicle due to overheating

4. A fine or removal of the vehicle registration number because the car is not roadworthy

But what does white smoke from exhaust mean? White smoke is not always a cause for concern. Because if your car smokes white, a technical defect does not have to be the cause. Under certain conditions, white smoke is normal to come out of the exhaust.

What Causes White Smoke From Exhaust 

Before you get scared, take your time for a closer examination. White smoke from the exhaust when accelerating is a relatively normal thing to happen during the winter. But, the heated exhaust smoke dries the exhaust system, so the white vapor should dissolve soon.

Further investigations are necessary only if the white smoke doesn´t disappear and occurs regularly. Water should only be able to enter the combustion chamber through the cooling system.

The cooling system regularly flushes the engine with a coolant mix of water and antifreeze. If the cylinder seal, the interface where combustion chambers and cooling systems are together, burns out. As a result, the water enters the combustion chambers.

You can determine if this happened by doing the following:

1. First, turn off the engine and check the pressure on the vehicle’s water hose. Allow the engine to cool down a little, and then open the cover of the expansion tank or the radiator.

2. Fill up the coolant and run the engine with the expansion tank or radiator open. Check the behavior of the water. If you see that bubbles are beginning to form, this indicates damage to the cylinder head gasket, and you should consider an exchange.

No Need To Worry – Sometimes It’s Just Water Evaporating In The Exhaust Pipe 

After starting, the exhaust gasses flow through the exhaust on their way to the outside. Since the exhaust gasses are very hot, the exhaust is heated. If there is water in the exhaust, it will begin to evaporate under the influence of heat.

It shouldn’t surprise you that water in the exhaust system evaporates after the engine has started because the exhaust can get very hot. This is especially true when the engine is running, but the car is stationary.

The faster you drive your car, the hotter the engine gets. One would think that this should also apply to the exhaust. However, it is cooled by the airstream and can reach temperatures between 100 and 300 degrees when driving.

But when the car is standing still, there is no cooling wind. In this case, the temperature in the exhaust system can reach up to 500 degrees. If there is water in the exhaust, it evaporates immediately.

It, therefore, only needs a few centiliters of water, and white smoke comes out of the exhaust after starting. Once the water in the exhaust has evaporated, the white smoke will disappear immediately, and the colorless exhaust gasses will flow out of the exhaust again.

Technical Defects Cause More Than Just White Smoke  


1. Bubbles In The Cooling Water:  

If the engine block or cylinder head has a hairline crack or the cylinder head gasket is defective, water from the cooling system will get into the engine’s combustion chamber. One would think that the pressure in the cooling system would drop as a result.

However, the opposite is the case. Due to the high pressure of each ignition, exhaust gasses penetrate the cooling system through the hairline crack. As a result, the pressure in the cooling system increases and can lead to excess pressure.

Overpressure in the cooling system has visible consequences. For example, the cooling hoses are bloated and hard. The water in the radiator tends to form bubbles and can smell like exhaust fumes.

2. Oil In The Cooling Water:  

Oil can penetrate the cooling system due to a defective cylinder head gasket or a crack in the cylinder head. The mixing can be recognized by the brownish discoloration and the oily, shimmering surface of the cooling water.

Therefore, check the consistency of the cooling water regularly. If it smells of exhaust fumes, if it has an oily shimmering surface or if bubbles form, you should go to a car workshop immediately.

3. Cooling Water In The Engine Oil:  

Just as engine oil can get into the cooling water, cooling water can get into the engine lubrication. As a result, the engine oil turns yellowish-creamy. Sometimes a milk foam-like substance will form, which you can find on the oil gauge and inside the oil cap.

4. Engine Temperature:  

If cooling water gets into the engine or oil gets into the cooling system, the engine will no longer be sufficiently cooled. The result is a rapid rise in engine temperature. Always pay attention to the temperature with white smoke.


Often it helps to determine if there is a serious problem or a technical defect when white smoke from exhaust emits by just driving the car for a longer distance.

So you would already know if there was just some liquid evaporating from either the exhaust or the engine. If that doesn´t help, follow the suggestions in this article and consult a professional mechanic in case the white smoke is still coming from your exhaust. Read more blogs here to know about car.