What does White Smoke from the Car Exhaust Mean
A change in the color of the smoke coming from the exhaust pipe of your car is a sure sign that there has been some kind of fault of varying severity. It could simply be due to an accumulation of condensation and may not have any negative implications. On the other hand, it might be an indication that the vehicle is breaking down, and there could be serious consequences if you don't act quickly. At oneHOWTO we'll explain what white smoke from the car exhaust means.
White smoke when starting the engine
If you see white smoke coming out of the car exhaust pipe in thin wisps, but it's only when you start the engine, then there's no need to worry. This is due to an accumulation of condensation that finds its way out through the exhaust pipe.
If the car has a diesel engine, lots of white smoke coming out of the exhaust when you start it up indicates that the fuel pump injection timing is off. You must bring your car to a mechanic to check this issue and, if necessary, fix the fault. You can also check your fuel pump injection timing yourself to know if this is the cause.
Coolant or anti-freeze leackage
If white smoke continues to come out of your exhaust while the car is running, and not just when you start it, it may be leaking coolant which is then being burned. This problem is not very serious but you must go to a professional mechanic as soon as possible to fix the leak. Usually, white smoke comes from the back of your car when water or anti-freeze enters your cylinder, and the car’s engine starts trying to burn it with fuel. Actually, the white smoke that you see coming out is steam. Head gaskets and other special gaskets keep the anti-freeze from entering your car’s cylinder area. The cylinder is the place where the air mixture and fuel are burnt after compressing. Anti-freeze that enters the cylinder that then produces white steam that comes out from your car’s tailpipe area. The anti-freeze gets into the cylinder probably because the engine got overheated and the head gasket failed because of excessive heat. Due to this, anti-freeze was allowed to enter the cylinder, from where the problem started. You will have to stop your car and check if there is a coolant leak immediately in order to fix the problem.
Your coolant may also have run out in which case you will need to stop the car immediately as it will be overheating. Check the levels of coolant to make sure this is the problem and follow these steps to know what to do if your car overheats.
White smoke depending on thickness
White smoke coming from the back of your car can be ignored if it is thin like vapor. This is probably coming because of normal condensation build-up in your car’s exhaust system, especially if it has undergone damp or cold climate conditions. It is normal, nothing to be concerned about, and will disappear quickly.
If you haven't used your car for a while, then once you start it up again thin smoke may come out if you haven't recently re-filled the gas or added any fuel stabilizer. In this case, we advise you to add some fuel stabilizer or to drain the old gas and re-fill it with fresh gas.
But if the smoke is thick, it can be a big problem. It may be caused because the engine is burning coolant. This may be due to a serious issue, like blown head gasket, damaged cylinder head, or cracked engine block. These are costly repairs, and need to be attended to immediately. Even small leaks in the coolant may lead to overheating, and cause serious damage to your car’s engine. Coolant may also end up mixing with the oil, and thus causing serious damage to your beloved vehicle.
Fuel filter related problems
The fact that the car is emitting a lot of white smoke from the exhaust when it's already running can be a sign of more serious and costly problems, and it should be repaired as soon as possible. The smoke could indicate more serious problems with the fuel filter, cylinder head, the cylinder head gasket or even a crack in the engine block. Keep in mind that problems of this kind can be quite costly.
What to do when your car is emitting white smoke
If you see white smoke coming from your car’s exhaust make sure you follow this procedure:
- Stop the car immediately and check and make sure that there is a proper amount of anti-freeze in your car’s radiator, change it if needed and also the over-flow bottle.
- Also check if anti-freeze has contaminated your car’s engine oil. You can check the engine oil dipstick, and also the under-side of the engine oil filler cap. If you see contamination with anti-freeze, which will look like a chocolate milkshake, you should not start your engine, and contact a mechanic as soon as possible.
- If you continue driving your car with contaminated oil, it may cause serious damage to your car’s engine, which will end up in extremely costly repairs and replacements.
Now you know the reasons, take a look at how to stop white smoke from the exhaust, you'll find solutions no matter what the underlying cause is.
If you regularly keep up with the maintenance of your car, you can detect these problems early, before they become expensive or even impossible to repair.
If you'd like to read similar articles to What does White Smoke from the Car Exhaust Mean, we recommend you browse around our Car Maintenance and Repair category.
- Do not overlook the problem if white smoke is coming out of your exhaust as it could be a serious issue for both your car and other drivers on the road.