White Smoke From Exhaust : Causes, Fixes And Repair Cost


White smoke coming from the exhaust in a vehicle can be a serious problem, which is always a sign of a problem with the vehicle’s engine. However, the presence of white smoke depends on the problem in the engine.

Because sometimes white smoke comes for some time only at the start of the engine. After that, no white smoke is visible. But in many severe cases, white smoke is visible continuously and always from the exhaust. Even if the engine has reached its operating temperature,

In this article, we will learn in detail about all the causes of white smoke from the exhaust so that you can identify the engine-related problem by looking at the condition of the smoke in your vehicle.

What Does ”White Smoke From Exaust” Mean?

White smoke coming out of the exhaust means that coolant or oil is burning along with the engine’s combustion process.

Why Does White Smoke Coming From Exhaust?

The main causes of white smoke from exhaust are cracks in the engine block, blown head gaskets, cracks in the engine head, damaged piston rings, bent engine head valves, or damaged valve seals. Additionally, turbocharger failure, engine overheating, bad fuel injectors, or bad glow plugs can also cause white smoke from the exhaust.

Let us know in detail all the causes of white smoke from exhaust, one by one, so that we can timely identify the causes of white smoke in the engine.

1. Cracks In The Engine Block


The engine of the vehicle is made up of two main parts, which are called the engine block and head, and in these two parts the other parts of the engine are fitted and joined tightly with nuts and bolts.

In the engine block, a gallery is made to rotate the circle of oil and water (coolant), due to which the engine oil reaches the top head and the water (coolant) keeps the engine temperature constant.

But sometimes the engine block gets cracked due to overheating or any other reason, due to which the engine oil and coolant mix and reach the combustion chamber and interrupt the combustion action on the piston.

Due to this, complete combustion is not possible in the fuel combustion chamber, and the engine starts showing white smoke through the exhaust and sometimes the engine shuts down or starts misfiring, which adversely affects the performance and mileage of the vehicle.

2. Blown Head Gasket


Head gaskets are placed between the two parts to connect the head and block of any small or large engine, which prevents engine oil from reaching the engine head above the engine block gallery, into the combustion chamber and also blocks coolant and air leakage so that the cooling and lubricant circles of the engine can function properly.

But sometimes the engine overheats while running due to some other reason, due to which the head gasket of the engine gets damaged. And the engine oil and coolant mix and go into the combustion chamber. Due to this, the fuel combustion process inside the engine is interrupted. Due to which the engine of the vehicle starts showing white smoke.

3. Cracks in The Engine Head


The engine head is a key part of the engine in every vehicle; it cycles the air intake and burnt gases of the engine at the right time according to the timing of the engine piston. This work is done by head valves and seals in the engine head.

To lubricate the engine head, oil is pumped from the engine block to the engine oil head through an oil pump to lubricate the working parts in the engine head.

But sometimes, due to overheating or any other reason, there is a crack in the engine head, due to which engine oil starts leaking from the engine head, and this leakage of oil starts going over the piston in the combustion chamber, due to which the engine starts leaking. The combustion process is disrupted and can cause white smoke to appear from the exhaust.

4. Damage Valve Seals

Valve seals in the engine head prevent oil from leaking into the combustion chamber. Because oil circulates in the head to lubricate the camshaft and rocker engine, For this, engine oil comes from the engine block to the engine head through the oil pump and lubricates the parts of the head. But the head valve and seal get damaged during long-term head parts work.

It can also be caused by engine overheating, which causes engine oil to leak through the valve seals onto the pistons, disrupting the engine’s combustion process and causing white smoke to come out of the engine.

5. Bad Fuel Injector

how to clean a fuel injectors

Fuel injectors are an important part of every vehicle’s engine. No engine can start without them. Fuel injectors spray fuel according to the piston of each cylinder in the engine. Due to which the gases heated due to the pressure of the piston start the combustion process.

But sometimes, due to various reasons, the fuel injector is not able to dispense the fuel spray in the right proportion. Due to this, the fuel cannot be combusted in the right amount over the piston, and the engine starts giving off white smoke. For this reason also, white smoke can be seen coming out of the exhaust of the vehicle.

 6. Leaking of Intake Manifold


In every vehicle engine, it is necessary for the oxygen to come into the combustion chamber in the right proportion for the combustion process to take place smoothly, which comes through the air filter. But sometimes the intake manifold on the engine can leak from some place.

In that there is no stability in the ratio of air. The engine may also show white smoke due to the poor fuel-air ratio. The white smoke that is seen coming out of the exhaust of the vehicle.

7. Failure Oxygen Sensor

oxygen sensor

The oxygen sensor signals the amount of oxygen to the vehicle’s ECU, based on which the ECU sends the fuel with the correct firing ratio and timing. So that proper combustion can take place in the combustion chamber of the engine. But the faulty oxygen sensor either doesn’t send the data for this oxygen ratio or sends the wrong data.

In this process, the combustion process of the engine is interrupted, which can also cause the engine to emit white smoke. That’s why you see white smoke coming out of the exhaust.

8. Damage Piston Rings

Pistons, rings, and sleeves are the main parts of every engine for its smooth operation. Without it, the engine does not start. The piston ring and sleeve inside the engine prevent compression pressure from reaching the middle block during combustion, which causes the piston to move up or down and turn the engine crank.

But sometimes, due to overheating of the engine or low or exhausted engine oil, the engine’s piston rings and sleeves wear out and get damaged.

Due to this, a tiny gap forms between the piston ring and the sleeve, causing compression leaks. Due to this, the compression hits the oil in the oil chamber below, forcing the engine oil to flow over the piston, and the combustion action above the piston causes the engine oil to burn, due to which white smoke starts coming out of the engine.

9 Engine Over Heat

Any engine runs on the basis of a specified normal temperature. The normal temperature at which all parts of the engine operate properly is about 40 degrees, but sometimes a technical fault occurs in the cooling system of the engine while it is running. Due to this, the engine temperature is unable to remain constant.

And with the engine running in this condition, the engine temperature rises excessively. which causes the moving parts inside the engine to sizzle due to overheating.

And due to the high temperature, engine oil starts burning. Due to this, white smoke can be released in the engine. For this, reason can also be white smoke can be emitted from the exhaust of the engine.

10. Failure Turbocharger


Many engines have a turbocharger installed, which recycles the gases coming out of the engine and sends these gases with high velocities to the combustion chamber of the engine, due to which the engine provides more pickup and performance. There is a core inside the turbocharger.

A small fan with which the vacuum and pressure of the air inside the block of the turbocharger are rotated very rapidly through a shaft. The fan and shaft of the turbocharger are lubricated with engine oil.

For this, engine oil is supplied to the turbocharger through a pipe from the engine block. The turbocharger has metal bushings at both ends of the shaft. which keep the shaft stable, and lubricants prevent engine oil from leaking out.

But sometimes lubricated engine oil leaks from the turbocharger and enters the combustion chamber of the engine along with the air. Due to this, the combustion action of the engine is interrupted, and when engine oil is burned with fuel, the engine starts showing white smoke.

How To Fix White Smoke From Exhaust

If white smoke is also coming out of the exhaust, do not ignore it. These can cause serious problems for your vehicle. Even the engine of your vehicle may be badly damaged and seized, and the engine may need to be overhauled.

First of all, if you notice any symptoms of white smoke in your vehicle, get it inspected by an expert mechanic at a certified garage, and he will tell you if there is any problem in your vehicle causing white smoke to come out of the engine.

1. Check the fuel injectors

If white smoke is visible in your vehicle due to the fuel injector, get the fuel injector cleaned with a high-pressure machine. If the fuel injector cannot be cleaned or repaired, you are left with the option of installing a new fuel injector.

2. Replace the oxygen sensor

Because the vehicles have oxygen sensors installed. White smoke can also be seen in the engine of the vehicle due to a malfunction in the oxygen sensor. But these symptoms and causes can occur in many working vehicles.

3. Check the turbocharger

If there is white smoke coming from the exhaust, check the intercooler and see if there is oil in the intercooler or not. If there is a large amount of engine oil leaking from the intercooler, this is a sign of turbocharger failure, and you may need to repair or replace the vehicle’s turbocharger.

4. Check the coolant system

After this, ensure that the engine temperature does not exceed that while the vehicle is running or in an idle state. If the engine of the vehicle gets too hot, it may cause the problem of white smoke coming out of the engine.

Therefore, check the engine cooling unit properly and get it repaired. Even after this, if the problem of white smoke coming out of the engine of the vehicle does not go away, then the engine head of the vehicle can be opened.

5. Check the head gasket

Open the engine head and check if the engine head gasket is damaged. If there is a fault with the head gasket, replace the head gasket with a new one.

NOTE: Be careful to never copy or combine quality head gaskets. Using a poor-quality head gasket can sometimes cause the engine to sound thick and heavy. Therefore, fit only the original head gasket from the company.

6. Check Engine Head

Check for cracking and flaking in the engine head. If the engine head is damaged in any way, have the head repaired or replaced with a new one.

7. Check for manifold leakage

For the combustion process to run smoothly in the engine of every vehicle, it is necessary to have the right proportion of oxygen in the combustion chamber, which comes through the air filter. But sometimes the intake manifold of the engine may leak from someplace.

8. Check the valve seal

If any defect is found in the valve seals of the head, replace the valve, fit it into the valve seat of the head, and replace the valve seal with a new one so that the valve seal of the head does not leak.

9. Check the piston rings and sleeve

After this, you have to check the piston rings, and sleeve of the engine. If there is a slight gap between the piston ring and the engine sleeve or if there are scratches on the sleeve, Therefore, you may be advised to install a new ring, a new piston, and a new sleeve. This could be an engine overhaul process, which is a high-cost and time-consuming process.

Cost To Fix White Smoke From Exhaust

On average, the cost to fix white smoke coming from the exhaust due to some common causes can range from $150 to $800. This may include mechanic’s labor and general repairs and diagnostics.

But if an engine part needs to be replaced, the cost from engine head repair to engine overhaul can typically range from $2,500 to $4500, more or less depending on the size and model of the vehicle.

The cost to fix white exhaust smoke depends on the vehicle’s engine problem and the size and model of the vehicle.


Q. How do I fix white smoke from exhaust?

To fix the white smoke in your vehicle, get the problem in the engine of the vehicle diagnosed by an expert mechanic. Usually, this problem comes from the failure of the engine head gasket, valve seals, and piston rings, sleeves. So these engine problems have to be fixed.

Q. What causes white smoke to come out of the exhaust?

There can be many reasons for white smoke in the engine of the vehicle. But the main causes can be bad fuel injectors, blown head gaskets, engine heads or block cracked or damaged, bad valve seals, damage piston rings and sleeves.

Because of all these reasons, there is engine oil or coolant in the combustion chamber of the engine. Due to this, burning during the combustion process of the engine produces white smoke.

Q. Can I drive with white smoke from the exhaust?

White smoke in any engine is a serious problem. When white smoke comes, one cannot drive any vehicle continuously for a long time, because this can lead to engine overhauling conditions and it can be completely closed. And this can also disrupt other parts working with the engine.

Q. Can a faulty injector cause white smoke?

If the fuel injector in the combustion chamber of the engine is spraying too much fuel due to failure. And most of the fuel does not burn properly. So white smoke can come from the engine, which is mostly seen in diesel engines.

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