We are reader supported. If you buy through the links on our website, we may earn a small commission at no additional cost to you. Our endorsements are strongly based on our intensive research online and we do not accept payments or gifts in return. Learn more.
Early diagnosis can save a lot of money and time, both when it is our health problem and when the problem is with our car.
If you see white smoke from exhaust of your car, it is better that you try to understand the actual reason behind it before it gets worse. It can happen due to many reasons, from condensation to head gasket failure.
Is it that bad?
As long as your smoke is not that thick, you might be safe. But hey! It is always better to be aware of what’s happening.
White smoke from exhaust: Possible reasons
Let’s check the main reasons behind the white smoke.
1. Steam due to condensation
If the white smoke from exhaust was seen on a cold winter day at the engine startup, there is nothing to worry about. This is nothing but the steam due to condensation.
As the engine warms up, this steam will disappear, usually after four or five minutes. You can check it by pressing the accelerator to a higher rpm when the car is on idle. However, pressing the accelerator is not recommended when you have just started the car.
Try it after driving for a few minutes. If thick white smoke is still coming, it might not be due to condensation.
2. Coolant Leaks
The white smoke from exhaust can be due to internal coolant leaks also.
In this case, the engine coolant is entering the combustion chamber due to the leak. The white smoke is accompanied by a sweet odor most of the time, but it depends on the coolant you are using.
You can check your coolant levels to know if the white smoke is due to the leak. If the coolant level is low, the white smoke could be due to coolant leaks and you should get your car repaired as soon as possible.
If you don’t fix this, your engine might get damaged over time.
3. Cracked Cylinder Head
This is the worst cause.
A cracked cylinder head, a cracked engine block(housing of cylinders) or a head gasket failure can also cause white smoke from the exhaust. These usually result from a poorly maintained cooling system.
A car owner is expected to change the coolant from time to time, to avoid the above-mentioned problems. The cylinder head gets cracked due to engine overheating, which causes the coolant to enter the combustion chamber and burn up, hence the white smoke from exhaust.
The coolant levels will go below the specified limit, and also it will become dirty if not changed on time, which can cause engine overheating.
You might have to get it fixed now, but you won’t have to in the future if you change the coolant on time!
4. Damaged Fuel Pumping Injection
If the white smoke is from a diesel car, it can be due to a damaged fuel pumping injection, which is responsible for pumping diesel into the combustion chambers.
When the pumping injection is damaged, the air-fuel mixture will not be in the perfect ratio, and that causes the white smoke from the exhaust. It is necessary to take it to a mechanic since the repair needs advanced skills and expertise.