White Smoke From Exhaust: 6 Causes And How To Fix It [A Ultimate Guide]

White smoke coming out of a car's exhaust is not uncommon, especially in winter. However, white smoke can be an unusual phenomenon in some cases.

If you see white smoke coming out of the exhaust pipe, accompanied by the car's heat, you need to find out the cause and quickly find a way to fix it.

There are many causes for this problem. To easily control and fix it in time, below is information related to white smoke from exhaust. Let’s check it out!

Main causes of white smoke from exhaust

Under normal circumstances, when white smoke appears within about a minute of starting the engine, you do not need to be too concerned about this problem.

If the weather where you live is easy to causes water vapor accumulation, the fact that the exhaust pipe emits white smoke does not pose too much of a risk.

However, if some unusual problems accompany the smoke, it is time to find out its cause. And here are some of the most common reasons you can consider:

1. Condensation of steam in the exhaust system


The steam buildup is one of the main causes of white smoke coming out of the exhaust. Fortunately, this problem is not too worrying.

Especially on cool-weather days, white smoke appearing is a completely normal phenomenon even when the temperature is low.

The above phenomenon usually only appears for a short time when you start the engine. The white smoke probably disappears in about 30 seconds to a minute.

2. Damaged cylinder

The cylinder head plays a rather important role, as it contains the intake and exhaust valves and is also responsible for adding fuel to the combustion chamber and discharging air.

With an important role, the cylinder head is one of the most vulnerable parts. When the cylinder is cracked, broken or damaged, the coolant will leak and dilute the engine oil.

When your engine oil gets mixed with the coolant, white exhaust fumes come out of the exhaust. In this case, the car owner should take the car to the repair center to assist in checking the cylinder and replacing it if necessary.

3. Leaking cooling water system

In addition to cylinder head cracking, faulty intake manifold gaskets also cause coolant leaks.

Intake manifold gasket problems can result from your vehicle having a water jacket running through the intake manifold. And one of the most obvious signs of this problem is white smoke coming out, accompanied by symptoms quite similar to the issue of a leaking cylinder head, and cracked cylinder head.

4. Poor fuel injector


Poor fuel injector

A fuel injector will be responsible for injecting fuel into the combustion chamber. When the fuel injector fails, jams or leaks, the fuel supply to the combustion chamber is immediately interrupted.

If the combustion chamber lacks fuel or the power does not appear in the room at the right time, white smoke will arise to warn of an abnormal injector operation.

In addition, you can also soon recognize the problem of fuel injection by several signs such as reduced performance, wasted fuel, reduced RPM limit, increased throttle, difficulty in starting, etc.

5. Engine controller error

Engine controller error

Cars emit white smoke due to ECU controller error

Another problem also related to fuel injectors is engine control. Engine control always needs to work correctly to allow the amount of fuel to stay balanced and controllable.

However, a malfunctioning motor control disrupts the balance. Of course, a problem with this part will not damage your injectors.

It will seriously affect the uptime of the fuel injectors, thereby causing unnecessary trouble related to the fuel injection amount of fuel in the combustion chamber.

6. Leaking valve body seal

The leaky valve body seal causes excess oil to enter the combustion chamber, mix with the fuel and ignite, causing white smoke when the car starts up.

In this case, the vehicle owner should bring the vehicle to a reputable maintenance center to check and repair and replace the valve body seals if necessary.

How to fix the problem of white smoke from the exhaust

After learning about the causes of unusual white smoke, you are probably now anxious to know how to fix the annoying phenomenon as soon as possible.

Each cause has a different solution. In some special cases, it is still better to seek the help of a qualified technical team. In other instances, you can refer to the following solutions:

Eliminate exhaust condensation: as mentioned in the previous section, all you need to do is wait for the condensation to disappear.

1. Check the gaskets

The gasket serves to distribute the combustion mixture, along with the coolant, to a separate intake port. These ports will be located in the cylinder heads. If damaged, the coolant will enter the port and into the combustion chamber, producing white smoke while driving.

How to fix: The driver must remove the intake manifold and check the intake gasket, if there are signs of leakage or rust you should replace them.

To resolve this issue, service personnel must remove the intake manifold and inspect the intake gasket.

2. Check cylinder head gasket

Remember to only do this step if the gasket is still in good condition. Then will check the head gasket.

This is a part of the vehicle used to seal the cylinder head to prevent coolant from entering the cylinder tube. A leak or damage to this element will allow the coolant to enter the combustion chamber. And finally, cause white smoke from the exhaust. If this part is still ok, then check the cylinder.

3. Check for cracks on the cylinder


Like the gasket, the cylinder head mouth can also crack and leak fluid. However, this is worse than having the gasket damaged because the replacement process will be more expensive and difficult.

4. Check cooling system pressure

If the vehicle emits white smoke along with an unpleasant damp smell due to the cooling water being burned, evaporating and the transmission oil burning. At this point, you need to review the coolant level and the gearbox oil level to determine the exact cause and handle it in time.

Check the cooling system pressure if the coolant tank is low in the water and the engine is overheated, and replace the engine cover gasket if necessary.

Add coolant and transmission oil immediately before performing repair steps. If necessary, take the car to the garage for a comprehensive inspection, to avoid a bad condition happening to the car.

5. Fix fuel injector problems 

Not every car owner can fix fuel injector problems. Some actions that you can do to solve this problem include determining the time the injector pump turns off and reprogramming the ECM. 

If the problem has already occurred, you will need to remove the injector clog or replace the camshaft.

Frequently Asked Questions (FAQs)

  • Why does the white smoke from the exhaust smell like gasoline?

White smoke coming out of the exhaust that smells like gasoline could be caused by a problem with the car's carburetor. At this time, the amount of fuel entering the carburetor is more than usual, leading to an uneven ratio of gasoline and oxygen, causing the gasoline to not be fully burned and follow the exhaust gas to the outside.

  • Why won't the car start but still have white smoke?

The car won't start but there is still white smoke coming from the exhaust which is an indication that lubricant is leaking inside the engine. Vehicle owners need to check the quality and signs of damage to the tank to take timely measures to replace it.

  • Why does white smoke appear when it's cold?

Normally, the phenomenon of white exhaust smoke when it is cold will occur in diesel engines because the fuel has not been burned or the liquid has not entered the engine.

To overcome this situation, vehicle owners need to bring their vehicle to a service center to have professional technicians check the oil level and quality of the tank and offer an effective solution.


As mentioned, only in the case of white smoke appearing and rapidly disappearing in less than a minute from starting the engine do you not need to worry too much about this phenomenon.

However, in case the above phenomenon persists, along with a series of other unusual signs, you will need to pay more attention to your motives.

With the instructions above, I hope you can identify the white smoke from the exhaust and find the right solution to prevent long-term losses.

If you still have any questions, do not hesitate to leave a comment below so that I can promptly give specific answers.

Finally, don't forget to share this article with your loved ones who may be experiencing the same problem. Chances are, it will help them in some emergency situations. Thank you for reading!

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