White Smoke from Exhaust: What Does It Means?

Although it’s good to leave the job to the professionals, we believe it is also wise to have some general information on what causes the white smoke.

What Does White Smoke Mean?

It is basically the result of steam that’s found itself inside your car’s exhaust system. However, you can determine whether it’s a big issue or not depending on how thin or thick the smoke actually is. For instance, if it is thin like vapor and disappears shortly after starting the car, then you have nothing to worry about.

The reason behind this is that most cars emit white smoke on startup then disappear when the engine and exhaust reach their natural operating temperature. In addition, it is good to note that the white smoke can also be emitted as a light shade of blue, which is an indication of oil entering the cylinders and getting burnt.

On the other hand, if the smoke is thick and is continuously present, you should be concerned. The thick white smoke mostly comes from a fault in the coolant system that usually leads to a major problem like a blown gasket, cracked engine block, engine overheating, or even a damaged cylinder head.

What are the Main Causes of White Smoke from the Exhaust?

As you have learned from the above question, there are various ways your car emits white smoke from exhaust pipes. However, we are going to look at the main causes of this issue.

01. Condensation

One of the main causes of white smoke is condensation. This usually happens when the weather is colder or when your car has been idling for some hours. The other factor that might contribute to the white smoke is when you go from a warm area to a cold one. So, what is condensation? Condensation happens when the warm exhaust gases meet cold outside air, causing steam. However, if this happens, you shouldn’t worry, since it usually goes away after a few minutes of driving.

02. Leaking Coolant

Another cause of white smoke is leaking coolant. The leakage will be noticeable when the smoke is visible while driving the car. Furthermore, there will also be a sweet smell coming out of the exhaust pipe. Don’t let this fool you as the sweet smell is a cause for concern.

There are several reasons why the coolant might be leaking; one of them could be from a cracked engine block or cylinder head. No matter how small the crack may be, there is a possibility of the coolant leaking into and contaminating the oil. When this happens, it will create thick, milk-like smoke.

03. Broken Fuel Injection Pump

It’s common to experience white smoke from exhaust diesel when the injection pump timing isn’t working. What does this mean? Simply put, the fuel injector is usually responsible for adding fuel to the combustion chamber. Therefore, if your car has a defective fuel injector, white smoke will form due to the improper amount of fuel added. It’s not advisable to check the injection or try to change it on your own. This is a job best left up to the pros.

04. Oil Leak

Oil is an important factor when it comes to your car operating properly. However, it can leak out of the valve seals or piston rings and flow into the internal combustion chamber, thus mixing with the fuel. If this happens, it will cause white smoke or even blue smoke to appear from the exhaust pipe. It’s recommended to fix the oil leak as soon as possible in order to avoid any further issues or damage.

05. Engine Control Unit Error

Finally, a faulty or glitchy engine control unit causes white smoke to come from the exhaust. What the engine control unit does is throws off the timing of the injectors, therefore, creating an error even though the injector itself is not damaged. The good news is that all you need is to fix or reprogram the control unit and restore the correct timing of the fuel injection pump.

One way to fix this issue is by simply unplugging your car’s battery for a few minutes to reset the computer. If that doesn’t work, visit your mechanic.

How Do You Fix White Smoke from Exhaust?

There are various parts of the car you should check to determine why your exhaust gives off white smoke. One of them is the head gasket while the other one is the coolant. There are several steps you need to take to be able to fix the white smoke issue.

Intake Manifold Gasket

Check Out The Intake Manifold Gasket

The first thing you should check out when you see white smoke coming out of your exhaust should be the intake manifold gasket. As you know, this gasket seals the manifold not only transporting coolant to the engine but also oxygen. If the intake gasket gets damaged, the engine gets overheats due to the leakage of coolant, air, and gas. Keep in mind that the gasket is mostly made of rubber or plastic. Therefore it is prone to damage caused by extreme heat. Although it can get cracked or damaged, it can easily be repaired if detected early.

Further, Examine the Head Gasket

After checking the intake gasket, you should move on to the head gasket. This gasket is designed to seal the head to the block. Its main function is to so prevent the coolant from going where it is not supposed to. If the head gasket has an issue, it needs to be fixed immediately.

Look Closely for Cracks in the Cylinder Head

As you know, the cylinder head is connected to the engine block and head gasket. Due to the fact that it’s made of aluminum, it’s prone to warping or breaking if your car overheats, thus releasing the white smoke. Therefore, it is necessary to carefully check it and if you spot a crack, change it right away.

#Coolant Level

Inspect the Coolant Level

The first step is to open the hood of your car and inspect the coolant. However, don’t forget that the engine should be cool before you remove the radiator cap or reservoir cap. If the engine is hot, give it 30 minutes or so to cool down before you attempt to check the coolant.s.

Open the Coolant Reservoir

After you’re sure the engine has cooled off, open the coolant reservoir and see if the coolant level is the cause of the white smoke. One way to check the coolant is to look into the coolant chamber or put a stick into its reservoir and check how much coolant there is. Keep in mind that the stick will give you the exact amount of coolant left in your car, which is more accurate than just looking inside the coolant chamber (what else are you going to look at it with?).

Check Other Areas of the Engine

If the amount of coolant is adequate, it’s time to move to other areas of the engine such as the cylinder head, head gasket, and even the engine block itself. Check if these parts have any cracks or any damage that may lead to the coolant mixing with the oil or fuel. If it’s possible, you should also perform a cooling system pressure check to try to determine which part is actually causing the leak.

The Difference Between Diesel Engine and Petrol Engine White Smoke from Exhaust

The difference between a petrol and diesel car releasing white smoke is brought about by different problems. That’s why it is essential to know the main causes is.

Diesel Engine

When you encounter white smoke in your diesel-powered car, it means the fuel is not burning correctly due to a lack of heat in the combustion chamber. The un-burnt diesel does not only cause white smoke but also contains certain toxins that will likely sting your eyes.

There are several causes of white smoke in a diesel-powered car. These include:

Water mixed with the diesel, which is mostly in the cylinder head or block or is caused by a cracked head gasket.

Damaged injectors
Low cylinder compression
Broken injection timing
Cracked or damaged rings or cylinder liners
Damaged fuel lines
Low fuel pressure to the fuel pump
Incorrect or broken fuel pump timing
Broken crankshaft keyway

Most cars experience a coolant leak when a broken head gasket or cracked cylinder head or damaged engine block is at fault.

Petrol Engine

Just like diesel-powered cars, the petrol engine has various causes that result in white exhaust smoke. Before we look at the causes, it is good to note that white smoke in a petrol engine is caused by water entering the cylinder and mixing with the fuel.

Basically, the white smoke is steam and is kept away from the cylinder by the head gaskets. Inside the cylinder, a mixture of fuel and air mix together, compresses and finally ignites to enable the car’s engine to function properly. Therefore, any amount of water that enters this area will produce steam that is presented as white smoke in the exhaust pipe of your car.

If white smoke is present, all you have to do is check for the proper amount of water inside the radiator and the overflow tank. Don’t forget also to check if the engine oil is also contaminated.

So, which are the other common causes of white smoke?

Engine Overheating
Faulty fuel pump
Broken injection pump
Best Automotive Smoke Machine Reviews or valve timing
The damaged or broken fuel injection system