6 Causes Of White Smoke From Exhaust

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A car’s exhaust system comprises multiple parts. These include the pipes, the exhaust manifold together with the cylinders, turbocharger, catalytic converter and a silencer to reduce the noise. So, multiple components can cause white smoke from the exhaust.

If you’re using an aftermarket kit, you can even increase the engine’s power and reduce the stress on the entire system, but that’s a story for another time.

Why is white smoke coming out from the exhaust? There are multiple causes, but most common are condensation, leaking in the cooling system, damaged cylinder, cracked engine block or fuel pump injection problems.

What is causing white smoke from the exhaust? Check 6 reasons and potential fixes

1. A leak in the cooling system


Usually the white smoke, it’s not visible on the startup. It takes some time until the coolant can reach the engine and contaminate the oil.

You can smell a sweet aroma along with the white smoke if this is the problem.

The mix of oil and coolant liquid will look like a pearly/milky curtain. Only a few drops of coolant is enough to create a combination that will give you a white smoke from exhaust.

This is a serious problem and can cause a lot of problems in time. The coolant level should be checked and the level should be in the parameters. A lack of coolant will cause the engine to overheat. The chain reaction continues with the head gasket that will not seal properly anymore because of the high temperature.

It will damage a lot of components in time and the engine will wear out way faster if we do not take the necessary measures.

2. Condensation from the exhaust pipe

This cause it’s one of the least problematic and serious. When it’s cold outside the car’s exhaust system it’s also cold.

By starting the car, it evacuates gases. The temperature of the gases, it’s higher than the outside temperature and also of the final pipe.

This will cause condensation on the exhaust final pipe and thus the white smoke from the exhaust. Usually this takes some minutes until the temperature of the final exhaust components it’s reaching a higher value.

It’s a good idea to be careful, as if the smoke it’s not disappearing, other motives can be the root cause.

3. Engine overheating


This is mainly caused by the head gasket. This sits between the engine block and the cylinder head.

The main purpose of this gasket is to avoid coolant or oil leakage in the cylinder’s area. It’s the most important sealer in any engine, as a defective one will cause a lot of damage and unwanted events.

A low coolant level can also cause engine overheating.

4. Damaged cylinder head

The cylinder head is the part that is sitting above the cylinders. This whole systems form the combustion chamber. Most likely this component can be damaged by overheat.

Over this joint, we place the head gasket.

Any crack in this system will cause leakages of the coolant, which will cause the same white smoke from exhaust.

These are more expensive repairs that need to be carried in specialized services.

5. Cracked engine block

The engine block contains the cylinders and the coolant access ways. The same as the issue above, cracks in the engine block can cause white smoke to emerge.

Check how the car exhaust system works:

6. Fuel pumping injection problem


With a diesel engine, the injector pump is more complex. The timing when the fuel is injected should be very precise.

In case the timing stopped working correctly, the amount of fuel that is entering the combustion chamber is higher. Rich fuel and lower air mixture will cause the fuel to not burn completely and be evacuated to the exhaust.

This smoke might not be white and can have a gray display.

What other people ask about the white smoke from exhaust?

What causes white smoke to come out of the exhaust?

While there are multiple causes of this issue, the white smoke coming out of the exhaust can be easy or difficult to fix. The most common cause is the condensation or coolant that is mixing with the oil. More serious problems include the cylinders, head gasket or engine block itself.

Is white smoke normal from exhaust?

Usually a good exhaust system will not release any white smoke to the outside. The only time that the white smoke is normal is when it’s cold outside.

A temperature difference will cause condensation on the final exhaust pipe and white smoke until the car warms up.

How do you stop white smoke from exhaust?

The most logical steps to follow when you want to fix or inspect the issue are:

  • check the outside temperature, if the smoke it’s caused by the cold weather
  • check the coolant level and figure out if you have a leak
  • verify the intake gasket that is sealing the intake manifold against the cylinder’s heads
  • establish if the head gasket is properly fixed or has damages
  • inspect the cylinders head for coolant or other liquids

Can I drive my car with white smoke?

You can drive it only if it’s the cause with the least impact, meaning condensation. If other components are failing or coolant it’s mixing inside the combustion chamber you can do more harm to your car.

The best solution is to discover the problem and then use the car in its normal parameters.

Can bad spark plugs cause white smoke?

Usually bad spark plugs cannot cause white smoke. The spark plugs ignite the fuel/air mix and a worn-out spark plug can cause your car jerking on acceleration or engine trembling.

Can a PCV valve cause white smoke?

A faulty Positive crankcase ventilation (PCV) valve can cause white smoke if the mixture of fuel/air is lacking enough fuel. The same issue can also happen in the case of a problematic fuel injector.

Usually these things make the engine a lot louder than usual.


Either if it’s a simple or more complex issue, white smoke from exhaust should not be ignored. As this is not a normal car behavior, it can damage a lot of components or even the engine.

It’s better to prevent a more costly intervention by taking care of the problem when it’s appearing.

Tell us if you had any problems with smoke coming out from the exhaust.

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