What does White Smoke from the Car Exhaust Mean

By Max. D Gray. Updated: July 25, 2017
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.

What does White Smoke from the Car Exhaust Mean - White smoke when starting the engine

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.

What does White Smoke from the Car Exhaust Mean - Coolant or anti-freeze leackage

White smoke depending on thickness

Thin smoke

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.

Thick smoke

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.

What does White Smoke from the Car Exhaust Mean - White smoke depending on thickness

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:

  1. 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.
  2. 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.
  3. 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. You can also take a look at the reasons for black smoke coming from the exhaust.

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 want to read similar articles to What does White Smoke from the Car Exhaust Mean, we recommend you visit 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.

Write a comment about What does White Smoke from the Car Exhaust Mean

What did you think of this article?
when i bought sienna oil was short and to much slash in the oil. we clean with some chemicals . no noise at engine but white smoke coming from exhaust . no antifreeze in the oil yet
Emmanuel Daniel
What makes motor to always vibrate when on motion
OneHowTo Editor
It may be your engine that is causing your car to vibrate, though there are several possible reasons for this. Take a look at this article, it may help:
my car only emits white smoke when sitting in traffic and usually only in first gear what could be the cause . thank you. oh it is a Peugeot 308 sport, 8 year old.
hie ..i have a ford telstar v6 1996 is producing a white smoke when i add some oil...but when the oil is not full there will be smoke only the tym i start the car.....

it is producing white smoke and drains the oil very fast
OneHowTo Editor
This may be due to condensation, but the fact that you run out of oil so fast may indicate you have a leak. It's best if you take your car to a professional so you can check it up properly.
Hope this helps
Janico Terry
Brake light comes on when driving at times. White smoke smelling like antifreeze coming from tailpipe at times. What could be the problem?
OneHowTo Editor
Sounds like your has a coolant leakage. This is why you should take it to a mechanic.

Hope this helps
Sanket N. Gawade
why dose my petrol car give off white smoke during first starting of the day...?? plz help me....
Jane Bertin (oneHOWTO editor)
If it's only at the beginning of the day, it's probably because of condensation being accumulated. If it's a lot of smoke, though, do have it checked out!
sreejith aman
My Nissan Qashkai also have the same problem heavy smoke coming from starting time only. Both white & black smoke coming 10 seconds time. And also i found the engine oil is burning and finishing. Last 3 months i am using the car in same condition but the problems not solved. Can you please tell me about it?
I have a Tahoe 2010 it puffs out a white cloud of smoke only when I first start it and it only last a few seconds does any one know what it is?
OneHowTo Editor
If your car is a diesel then it might mean that the fuel pump injection timing is off
Candy Ryan
When I start the car it is fine . No white smoke then I let it so an idle then white smoke is coming out of the tale pipe and under the hood what could that be? All my fluids are full.
Allen K Mathew
my car produce white smoke from exhaust while running (lesser amount of smoke,when i accelerate the pedal at high level) and engine oil drains out very quickly. Can anyone tell me what actually it is about

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