Why White Smoke from Exhaust? Causes and Solutions

Moving around in your new or old drive is so much fun until you start leaving a trail of colored smoke everywhere you go. Imagine causing air pollution every time you are on the go, frustrating, yeah? Black, gray, blue or white smoke from exhausts takes away all of the fun. This signifies various car problems, depending on the color, when it started, and how dense it is. As a driver, it is pertinent to pay attention to your car and spot out any unusual behavior as early as possible. This is why we have compiled this guide to give you a complete understanding of the various smokes from the exhaust, what they signify, how to fix them and other related problems.

Causes of White Smoke from Exhaust

Several factors may cause your car exhaust to emit white smoke. It could be a minor issue or a big problem depending on the density of the smoke. White smoke arises from the normal condensation of wispy vapors in the exhaust pipe. If the smoke is thin like air vapor, then, you have got no problem. The denser the smoke the bigger the problem, which may be cracked engine block, damaged cylinder head, or blown head gasket. Therefore, it is safe to monitor its progression so you can tell when there is an actual problem. Some of the causes of white smoke from exhaust include:

1.Faulty Coolant Reservoir Tank

Sometimes, white smoke does not emit from the exhaust while starting your car, it comes later when the car is on the run. This shows a coolant leak. The coolant can leak from a number of places, one of such is the coolant reservoir. A damaged coolant reservoir tank will cause an excessive leak of coolant, which finds its way into the combustion chamber and burns together with normal combustion mixture. Burning the leaked coolant causes your car exhaust to emit a huge amount of white smoke. Also, your car gets overheated without the coolant, leading to the emission of dense white smoke. You should repair or replace the reservoir as soon as possible to avoid other car issues.

2.Broken Fuel Pump

This is usually the cause of white smoke from the exhaust of diesel cars. The function of the fuel injector is to supply the necessary amount of fuel to the combustion chamber at the right time. If your car has a damaged or broken fuel injector, there will be an irregularity in the timing, causing it to inject fuel at the wrong time which eventually leads to the emission of white smoke from the exhaust. To stop white smoke from the diesel engine, you will have to carry out a thorough check on the fuel pump as a little crack even could cause wrong timing. You should take your car to the mechanic as soon as possible because a broken fuel pump has a grave effect on your car engine, which is the life wire of the car.

3.Cracked Engine Block

Having a crack in your car engine is the worst thing that could happen to you but it could also be the reason why your car exhaust emits white smoke. True, it is pretty costly to repair or replace but that should not deter you from taking it to the mechanic. Note that the longer it lasts the worse it gets.

4.Oil Leak

Normally, oil is needed to lubricate the engine parts so they last longer and not get worn out. But sometimes, the oil could leak out of the valve seals and flow into the combustion chamber where it is burnt alongside other combustion mixtures. This causes the exhaust to emit white smoke or blue smoke even. A quick remedy should be done because your car engine parts need to be lubricated.

5.The Error of the Engine Control Unit

Besides a broken fuel injector, a bad engine control unit may also cause wrong or irregular timing. So, in cases where the fuel injector is working well, you should run a quick check on the engine control unit as they could also influence wrong timing. This is a technical process, as such, it would require the expertize of a professional mechanic.

6.Cracked Cylinder Head

If your car were to have a cracked cylinder head, it will cause the flow of coolant out of the cylinder which could mix with the engine oil leading to contamination of the oil. A car with contaminated oil is sure to emit a huge amount of white smoke and a smell that is difficult to ignore.

You May Like: Why Black Smoke from the Exhaust? Reasons as well as Solutions

Solutions to White Smoke from Exhaust

Ignoring the problem only destroys your precious drive, causing you to spend more on repairs or replacement. Endeavor to do a regular check on your car, and when what seems to be a minor issue arise, be sure to monitor its progression so you know when to take the car to the mechanic. Better yet, take it to the repair shop immediately you notice an abnormality. If it is a minor issue, you could also try fixing it yourself. These are the steps you can follow to fix white smoke from exhaust:

1. Check the Intake Gasket

The function of the intake gasket of every car is to distribute coolant or combustion mixture to the different intake port on the cylinder head. In cases where the intake gasket is faulty or damaged, there will be a leak of coolant which spreads to the combustion chamber causing the car exhaust to emit white smoke. The first line of action is always to check the intake gasket for any leak or rust, as this is usually the case in most cars. But if the intake gasket is in a good working condition, then you should run a quick check on the head gasket.

2.Inspect the Head Gasket

The head gasket serves as a seal for the cylinder head, any damage or leak would lead to leaking of the coolant into the combustion chamber which eventually causes emission of white smoke from the car exhaust. A proper inspection should be carried out to confirm any malfunction. If none, then the cylinder head must have a crack.

3. Check the Cylinder Head for Crack

In most cases, there is a crack on the cylinder head if the head gasket and intake gasket are functioning properly. The cylinder head is prone to overheating, as such, you should always check if it is evenly sealed with the engine head and head gasket. If it is not, you should visit a mechanic immediately.

Also, you can read our another article Top 8 Head Gasket Blown Symptoms: Causes, Consequences, and Solutions

Related Questions

What are the causes of white smoke from the exhaust when starting a car?

Most diesel cars exhaust emits white smoke on startup, especially in cool temperature. The smoke appears like a vapour and fades in no time. You have got nothing to worry about. But if it is dense, then, there is a problem. You should check your car as discussed.

What are the causes of white smoke from the exhaust when accelerating?

This occurs when the coolant leaks into the combustion chamber of the engine as a result of a crack in the cylinder head or faulty head gasket. Your car burns fuel or diesel as it accelerates, if the coolant is in the combustion chamber, it burns too, giving the dense white smoke you see from your exhaust. You should get the car to the repair shop as soon as possible to avoid engine problems.

What are the causes of white smoke from the exhaust when idle?

This signifies the presence of oil in the combustion chamber and it is very easy to spot because the smell of burning fuel is way different from that of burning oil. When oil gets into the combustion chamber of the engine, it burns together with the fuel or diesel giving off a peculiar smell and heavily dense white smoke. It is advisable to fix it as soon as possible. The longer the condition persists the worse it gets putting the engine, spark plug, and other parts at risk.

How to stop blue smoke from the exhaust

Blue smoke from exhaust simply shows the valve seals or piston rings of the combustion chamber are worn out. And this causes the oil to leak out from where it is supposed to be lubricating moving car parts into the combustion chamber. In the combustion chamber, the oil burns along with normal combustion mixture and this ultimately lead to the emission of blue smoke from car exhausts. Also, if your car is turbocharged, it could mean that there is a problem with the turbocharger. You should look it out and either repair or replace it. The best way to stop blue smoke from the exhaust is by changing the oil and oil filter regularly.

How to stop gray smoke from the exhaust

It is quite difficult to ascertain the major cause of gray smoke as a number of factors are involved. Gray smoke from car exhaust could be as a result of a faulty turbocharger, an oil leak in the engine, or a problem with the transmission vacuum modulator. Like in blue smoke, the oil might have leaked into the combustion chamber or the turbocharger is faulty and requires repairs or replacement. Also, it could be that the automatic transmission fluid is being burnt in the engine which allows transmission fluid to leak into the combustion chamber and burn together with the combustion mixture. A stuck PCV (positive crankcase ventilation) valve could be the problem too.  Be sure to take your car to an auto-expert when your car exhaust starts emitting gray smoke as a number of factors could be responsible.

How to stop black smoke from the exhaust

Like other smokes, black smoke from exhaust also indicates a problem. This signifies that your car is burning fuel excessively. It is caused by several factors such as faulty fuel injector, clogged air filter, or issues with the fuel pressure regulator. To stop black smoke from the exhaust, you have to check the air filter, fuel injector, sensors, and fuel pressure regulator to see if they are in good working condition.

Watch this Video and Know Details of Exhaust Smoke Colors Meaning


It can be very difficult to tell the exact cause of dense white smoke from the exhaust. It could arise due to problems from other parts besides the aforementioned causes. This eventually leads to serious car issues irrespective of the cause. Thus, it is important you take your car to the repair shop immediately you notice a problem. It is cost effective too, because the longer the issue persists the worse the condition and the consequences gets. Fix it now!


Recent Posts