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White Smoke On Startup Then Disappears: Reasons & How To Fix It?

white smoke on startup then disappears

Are you concerned about the white smoke? Do you confused about white smoke on startup then disappears?

Leaks in the cooling system are the most typical source of white smoke that develops and then dissipates after starting. The exhaust pipe contains a liquid that acts as a coolant for the car’s engines. Additionally, the vehicle’s components will benefit from the lubricating provided by this substance. A leak in the piston ring may cause white smoke that dissipates during the beginning.

Usually, the engine starts, and the smoke rapidly dissipates. White smoke isn’t simply a problem for startups. White smoke may be visible from the exhaust pipe when accelerating or idling.

Do you notice white smoke at startup but goes away and don’t know how to fix it? Follow this blog!

White Smoke On Startup Then Disappears: Reasons

In the combustion process, gases are released through the exhaust pipe as a byproduct. Usually, these gases are not visible during the warmer months. 

On the other hand, winter driving results in the emission of thin, white vapors smoke from the exhaust, which vanishes after 5-10 minutes of driving. This smoke occurs on a regular basis and is caused by condensation.

If there is a continuous stream of dense smoke coming from the exhaust, that does not disappear. It shows the presence of internal coolant leaks and other engine issues. Let’s look at what’s causing the white smoke on startup.

  • Coolant leak.
  • Cracked cylinder block.
  • Bad head gasket.
  • Defective fuel injector.
  • Defective ECU.

Coolant leaks:

Exhaust smoke with a milky appearance and a pleasant scent is usually a sign of an internal coolant leak. The coolant’s principal function is to absorb engine heat and return it to the radiator.

White smoke may be seen coming from the combustion chamber when coolant is pumped into it. Additionally, engine oil becomes contaminated due to coolant leaks inside the engine.

A technician should be consulted if you feel that coolant leaks from your vehicle. Coolant loss might be caused by an open fracture in the cylinder head.

Furthermore, the cylinder and spark plugs are the finest places to look for leaks. Engine overheating is caused by a poor coolant or a malfunctioning cooling system.

Cracked Cylinder Block:

A cylinder block consists of a cylinder, a coolant channel, and cylinder sleeves all in one piece of metal. A broken cylinder head is a common cause of coolant leakage. Coolant can seep into the combustion chamber if the engine block or cylinder head is damaged.

White smoke is emitted from the exhaust pipe due to coolant leakage. Cylinder heads, blocks, and head gaskets are some of the most damaging engine components. These portions need a lot of work.

Because a fractured cylinder block is difficult to diagnose, it is recommended to have it replaced by a qualified technician.

Bad Head gasket:

A head gasket separates engine blocks and cylinder heads. The primary function of the head gasket is to keep the cylinder’s combustion gases contained.

It’s also essential to keep coolant and engine oil from leaking from the head gasket.

Faulty Fuel Injector:

Electronically controlled valves pump gasoline into the engine using a Fuel Injector. A fuel injector administers the correct amount of gasoline or diesel into the engine to maximize engine efficiency and combustion.

Because of this, the combustion chamber is fed with varying amounts of fuel. It produces white or grey heavy smoke because of the surplus fuel.

Based on the vehicle’s mileage, it’s easy to identify a bad fuel injector. The best remedy is replacing the injector, which is a pity.

Electro-mechanical control unit malfunctioning:

Engine control mode (ECU) is another name for ECU. The actuators in a combustion chamber are controlled by this electronic control unit to provide the best possible performance. A malfunctioning electronic control unit (ECU) may cause a decrease in the vehicle’s fuel economy.

White smoke is produced when the fuel injectors are out of rhythm with the pistons in an engine. If your vehicle’s ECU is malfunctioning, you may experience sluggish acceleration, reduced braking pressure, and a quick halt.

How to Fix White Smoke on Startup

white smoke on car startup

A damaged engine block, head gasket, or cracked cylinder head are all possibilities if you detect white smoke coming out of the exhaust manifold. If the coolant level is less than the reservoir, begin by checking the coolant level.

This symptom indicates leakage. In some instances, even when the coolant level is correct, the leaking persists. As a result, perform a thorough engine diagnostic and bring your vehicle to a repair.

The engine will be severely damaged as a result of this. So a total engine block, head gasket, or damaged cylinder head replacement is recommended.

How can you fix a leak in your cooling system?

Engine damage might be severe as a result of coolant leaks. Coolant leaks from the gasket might be difficult to pinpoint since it’s difficult to tell exactly where the leak is coming from. Antifreeze leaks cause a significant loss of coolant.

Furthermore, this might result in catastrophic engine damage. As a result, you must locate the source of the leak and stop it as soon as possible.

If you can still stop the coolant from leaking, get expert assistance. In addition, if you notice an exhaust leak, take care of it.

Is there a way to repair a cylinder head that has been cracked?

If you see signs of a broken cylinder head, you’ll need a costly repair or a complete replacement. To confirm a broken cylinder head, you must disassemble a half-engine to examine the cylinder block. However, a real and trustworthy technician is needed for this procedure.

Replacement of a defective head gasket

The engine may be overheated or leaking coolant without obvious leaks if you notice symptoms like poor performance, white exhaust, engine misfiring, and coolant loss. It indicates that the head gasket has been damaged or cracked. Repairing or replacing a head gasket can be costly and necessitates the services of an experienced technician.

Is there a way to fix a faulty fuel injector?

Fuel injectors that have become clogged are usually fixed by simply cleaning the nozzle. However, they might get completely clogged due to a lack of engine maintenance, necessitating a switch to premium fuel injectors.

A faulty electronic control unit can be repaired in several ways.

Contact the company that made your ECU to see if they can help you fix it. There are several online ECU repair services available.

When accelerating, what produces white smoke from the exhaust?

white smoke from the exhaust

If you detect white exhaust smoke coming from your car’s exhaust when it starts or accelerates, transmission fluid or burning coolant may be to blame. 

Exhaust gasses emitting white smoke and a burning smell may be caused by the engine sucking in transmission fluid through vacuum lines that are not supposed to be there.

To determine if your engine is overheating or leaking a head gasket, you may do a pressure test on the cooling system. A leaky gasket might cause white smoke coming from the exhaust on startup, and when accelerating, thus it may be necessary to repair it.

Changing the vacuum modulator valve or raising the fluid level to the correct height can solve this problem if fluid is the issue.

Comparing diesel and gasoline engine exhaust emissions

The Diesel:

According to the diagnostic, the white smoke that came out of your diesel engine’s exhaust on startup was caused by coolant or water dropping into the combustion chamber. 

A broken head gasket or fractured cylinder head is often to blame for coolant leaks in diesel engines.


This sort of engine’s white exhaust smoke on startup shows that the air and fuel mixtures aren’t correct.


Do defective spark plugs cause white smoke?

Spark plug failure is not indicated by white smoke coming from the exhaust pipe. The color white indicates the coolant leak, damaged head gasket or cylinder head, and fuel issues.

The EGR valve may create white smoke. Is it true?

As a general rule, black smoke is caused by an EGR problem rather than white smoke.

What does white exhaust smoke generally mean?

Coolant leaks may be seen in the exhaust by the thick white smoke from the tailpipe. Overheating from a coolant leak can cause severe engine damage.

Is white smoke a sign of a malfunctioning injector?

The faulty injector is indeed causing the engine to overheat and use more gasoline. A smoky exhaust indicates a problem with the injectors.

Can I Drive My Car with White Smoke?

You should avoid driving your automobile if the exhaust is emitting white smoke. What gives, you could ask? First and foremost, if your car’s gasket leaks engine oil, you may have an issue with your car’s engine. This might seriously harm or even ignite the vehicle’s engine. Because of this, if you observe white smoke coming from your car’s exhaust, have it looked out immediately.

When the engine is idle, why does white exhaust smoke appear?

When the automobile is idle, the most typical cause of white smoke is oil entering the combustion chamber (not necessary, implied).

The color and smell of oil are distinct from gasoline, making it easier to tell the difference between them. Remember that this issue must be resolved soon to avoid more harm, such as losing the spark plug.

Do you know why white exhaust smoke smells like gas?

Water vapor is the most common cause of white exhaust smoke that smells like gas. When water enters the combustion chamber, this occurs. Water drips from the exhaust pipes when this happens. 

Water in the gasoline should be replaced as soon as possible if it is found (implied). You should take your automobile to a repair as quickly as possible, even though most owners think it’s normal.


Do you understand the topic: white smoke from exhaust on startup then goes away? If not, then again, read the whole context.

When you first start your computer, you may notice a thin layer of white smoke rising from your computer’s fan. 

Condensation is the most common cause of wintertime white smoke. In rare cases, thick white smoke with an odor might signal coolant leakage or other engine problems.

A trained mechanic should handle maintenance and replacements. Everyone, in my opinion, lacks the right tools, leisure time, and expertise in car maintenance. Because of this, it is advisable to rely on a licensed technician. 

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