Most of us might have not looked at the color of the exhaust smoke ever. Being unaware of the importance of the color of exhaust smoke, we might have given an invitation to some unexpected damage to the internal parts of the vehicle.

Sometimes your little awareness and attentiveness save you from the catastrophic situation. And this is what we are going to talk about throughout this article that how we can identify and resolve the problem of thicker white smoke.

Let’s find out everything about white smoke and its consequences.

What Does White Smoke from Exhaust Mean

There is nothing strange seeing smoke to be coming out from the exhaust. What matters is the color of the smoke. If it is of thin white color smoke, it is due to normal condensation and there is nothing to worry about it. But if the smoke is thicker white color smoke then it could be an indication to some serious problem.

However, every time white smoke from the tailpipe is not a sign of a problem.

If it is winter, the smoke could be white due to low temperatures.

But if there is warm temperature and exhaust smoke is still white, then seriously there is some major issue.

And it is necessary to get this issue addressed as soon as possible so that any damage to the exhaust system and engine could be avoided.

Common Causes of White Smoke From Exhaust

If the exhaust system continuously emitting white smoke even after the engine has warmed up, it means some internal problem taking place. Before you diagnose the problem, it is essential to understand the reasons which can cause white smoke to blow out of the exhaust.

#1. Broken Fuel Pumping Injection

If you’re having a diesel car, faulty injector pump timing can cause white smoke from the exhaust. Due to the broken fuel pumping injection, neither the right amount of fuel will enter the combustion chamber nor the fuel will burn correctly and that will cause white smoke.

In such a case, you should approach to a professional mechanic who can check and replace the fuel pumping injection if it is required.

#2. Leaking Coolant

If there is leakage in the coolant, it can cause the exhaust smoke to be turned white.

Basically, when the coolant mixes with the engine oil, it makes the smoke look milky. Even if there is a small leakage, a small amount of coolant can affect the fuel burning process.

In the state of leaking coolant, the vehicle engine will start to get overheated which will result in failure of the head gasket. If it is not repaired in time, it may lead to severe damage in the internal parts of the engine.

#3. Oil Leakage in Piston Rings or Valve Seals

The white smoke from an exhaust could also be the result of oil leakage in piston rings or valve seals. When it happens, the leaking oil from piston rings or valve seals flow to the combustion chamber where it gets mixed with the fuel. The combination of fuel and oil causes white smoke to come out of the tailpipe.

The oil leakage severely affects the lubrication of the internal parts of the engine. The loss of lubrication leads to internal damage to the engine components that is a highly expensive repair.

Therefore, the case of white smoke from exhaust needs to be addressed on an immediate basis to avoid any serious mechanical problem in your vehicle.

Also, Read: Symptoms of Bad Piston Rings

#4. Faulty Engine Control Unit

If your vehicle’s engine control unit is defective, it will turn off the timing of the fuel injector that will result in the improper supply of the fuel as well as improper burning of the fuel in the combustion chamber. And this will cause white smoke to come out of the tailpipe.

In this scenario, you only need to reprogram the engine control unit. This will automatically correct the timing of the fuel injector. You just need to remove the battery for a minute and again plug in the battery, the fuel injector timing will get reset.

If it still doesn’t work with the correct timing, then you will need to get the engine control unit reprogrammed by a professional mechanic.

Also, Read: Symptoms of Bad Engine Control Unit

#5. Cracked Engine Block

Having a crack in the engine block is the most dangerous scenario

How to Diagnose White Smoke from Exhaust

There are a number of ways to diagnose a car with white smoke that tells you where the actual problem is in the vehicle causing white smoke. Let’s know about them one by one.

  1. Smell the Smoke: First of all, check the smell of the exhaust smoke, if it has a slightly sweet smell then look for the coolant level. If the coolant level is low and the engine is getting overheated, it means the head gasket is leaked that needs to be replaced.
  2. Check Coolant Leak: To test if the coolant system leaks, use a coolant pressure tester. Place this coolant tester inside the coolant system for 60 to 70 minutes and then check for any signs of coolant leakage. If you notice any sign, it means either the head gasket or cylinder head is cracked. And you will need to replace this component on an immediate basis to avoid any severe damage to the vehicle.

How to Fix White Smoke from Car Exhaust

Here you will find a number of solutions to the problem of white smoke but you should try these solutions only then if you’re well familiar with car parts and their working. If you apply these solutions without any prior knowledge then you may make the problem worse than before that will add to the repair cost too.

See, how you can get rid of white smoke from the exhaust.

#1. Check the Level of Coolant

If you think the coolant level can be the cause of white smoke. Check the coolant level. But make sure the engine has cooled down when you open the coolant reservoir cap else you may have to suffer from a serious injury.

When you open the reservoir, put a stick into the reservoir and see at what level the stick is wet. It will indicate to you about the level of coolant. If the level of coolant is sufficient, then look for other components but if it is low then add the coolant to the maximum level.

#2. Check the Intake Gasket

If even after maintaining the level of coolant reservoir, the exhaust pipe is releasing the white smoke then you should check the condition of the Intake Gasket that seals the manifold to the head.

This car part is responsible for distributing the combustion mixture along with the coolant to the intake port. It means if it gets damaged, the coolant will leak into the combustion chamber that will create white smoke when the engine would be in running condition.

Therefore, if you notice any crack or damage on this gasket then you should approach to the expert mechanic who can check this and replace it.

#3. Check the Head Gasket

If the Intake Gasket is working fine then check the Head Gasket. This car part seals the cylinder head so that the coolant cannot enter into the cylinder. If this part gets damaged, the coolant can easily enter the chamber where it gets mixed with the fuel and produces white smoke. If you notice any crack or damage on this part then get it repaired or replaced from an expert mechanic.

#4. Check If Any Crack Is In the Cylinder Head

If the Head Gasket is in good condition then you should check the cylinder head because it is made of aluminum that is more prone to get damaged especially in an overheated condition. To check this car part you will need to open the engine hood. During inspection, if you notice any crack even minor crack in the cylinder head then you should go for the replacement.

Causes of White Smoke From Exhaust on Startup

There could be a number of reasons that can cause white smoke from exhaust on startup. However, generally, it could happen either when the cylinder head is cracked or broken or the head gasket is faulty.

You may also see the white smoke if the engine block is broken. In all the cases, the coolant gets leak into the combustion chamber and then get mixed with the fuel that produces white smoke.

Therefore, if you find any of these car parts damaged or even minor cracked, visit the mechanic and get the repair done without any delay.

Causes of White Smoke From Exhaust When Accelerating

If you notice the white smoke when accelerating the vehicle then the possible reason could be that the car is absorbing excess transmission fluid. In this case, you will also experience the smell like burned oil.

Another reason could be either the cracked cylinder head or the leaking head gasket that is causing the coolant to leak and this coolant burns along with the fuel which produces white smoke.

If fluid is the problem then get replaced the transmission vacuum modulator valve and maintain the level of fluid.

Causes of White Smoke From Exhaust When Idle

If you notice white smoke from the exhaust when your vehicle is in idle condition, it means there is oil inside the vehicle’s combustion chambers. And when this oil burns off it produces white smoke.

Remember that in such a case the thing burns is the oil, not the gasoline. The longer the oil stays in the chamber the more risk is there to the spark plug which requires only replacement.

Causes of White Smoke From Exhaust When Cold

The white smoke from the exhaust is very common in the cold weather. Generally, this is the case with the diesel engine. This white smoke usually comes when the fuel or coolant remains unburned and it produces white smoke.

But it is not necessary in every case and the reason for white smoke could also be the incorrect injector timing in the cylinder. Therefore, if you notice white smoke even in winter, you must get it to check by a professional mechanic.

Causes of White Smoke From Exhaust Smells Like Gas

It may seem normal if you see white smoke from the exhaust that smells like gas. But it is not a normal condition, it is simply either due to the water dripping in the fuel or a leak in the head gasket that causes engine misfiring. Therefore, you should not neglect if you notice white smoke from the exhaust that smells like raw fuel.

Difference Between White Smoke from Exhaust With Diesel Engine & Petrol Engine?

The diesel engine and petrol engine have different reasons for white smoke from the exhaust. If it is the case with the diesel engine then white smoke generally comes out due to incomplete combustion where fuel remains unburned. And this fuel mist comes out from the exhaust in the form of white smoke. The reason for unburned fuel could be either the leaking coolant or water dripping into the combustion chamber.

The thick white smoke from the petrol engine generally happens due to a faulty coolant system. The coolant leak is the major cause that can happen either due to the damaged cylinder head, cracked engine block or broken head gasket. In every case, only replacement is the best solution.

Is it Safe to Drive a Car with White Smoke from Exhaust?

How dangerous it could be driving a vehicle with white smoke until you know the exact reason for the white smoke. If the source of the problem is oil dripping in the chamber then you may end up with engine misfire that can cause very serious damage to the vehicle engine.

Therefore, we recommend not ignoring if you notice white smoke no matter whether you have a petrol engine or a diesel engine. And do not drive the vehicle until you get it inspected and repaired by an expert mechanic.


In the end, we would again want to remind you that white smoke from the exhaust is not always normal. And overlooking the condition of white smoke can cause very serious damage to your vehicle depends on how long you delay for the inspection and repair.