White Smoke On Startup Then Disappears (What To Do?)

Your vehicle’s exhaust system is the piping that functions in guiding the gasses away from the internal combustion process in your engine. It will ensure that the engine is not filled with burnt fuel or burnt vapors because these will cause overheating and excess friction. 

If it will not work correctly or white smoke or strange colored smoke is coming out of the exhaust on startup, then this is a sign that you will need to fix it right away. 

All the car drivers would not want to start their vehicle and then have strange colored fumes come out of their exhaust while their vehicle is running. If you start your vehicle by turning the key in the ignition with a gas engine, you will notice a white smoke billowing out of the exhaust; there are a few reasons for this. There are specific reasons why it happens. 

It can be easily fixed also and with no complications. But there are a few reasons why the white smoke is coming out of the exhaust from startups, and some of them are severe and can also lead to some future issues. 

So in this article, we will talk about white smoke. Let us get started. 

White Smoke On Startup Then Disappears

What Causes White Smoke On Startup?

There are plenty of reasons why white smoke comes out of your vehicle during startup. Here are the possible reasons.

1. Condensation

If you live in a particular climate and colder climates, the condensation will build upon the window of your vehicle and its internal parts. So if it is cold outside and you notice white smoke from your exhaust on startup, it might probably mean a minor issue. On the other hand, if white smoke is coming out and is warm, look into it further.

2. Coolant Leak

If there is white smoke on your exhaust after the engine is warmed up, this can be a sign that you have a coolant leak in one of the pipes or engine of your vehicle. If there are coolant leaks, the engine will not cool down itself, and it will not provide the proper lubrication it needs for the parts. As a result, there’ll be overheating and excess reaction. 

The symptom of coolant leaking is white smoke coming out of the exhaust pipe. It will also leave an odor. 

A coolant leak is when there is damage to the cylinder head or an issue with the internal engine. The cylinder head is above the cylinders on the cylinder block and housing components.

3. Valve Seal Leak Or Piston Ring

If there is a leak on your valve seals or your piston rings are damaged, this can cause white smoke from your exhaust on startup. If this is the problem, the oil will leak into the combustion chamber, mixed with the fuel. 

4. Damaged Fuel Injector

A damaged fuel injector or faulty fuel injector will not deliver the proper amount of fuel to the combustion chamber. It might deliver too much or too little, disrupting the air and the fuel mixture. If it delivers too much fuel, the excel fuel will not be able to burn properly

5. Incorrect Injector Pump Timing

In diesel engines, you will need the perfect ignition timing and the fuel injector’s pump to turn the engine on. The engine will run rich and have a rich mixture if the timing is off. This will cause the fuel to burn and cause a cloud of white smoke from the exhaust on startup.

6. Transmission Fluid

It can mean that your engine takes up too much fluid from the vacuum pipe or the hose. This means that your vehicle is burning excess oil and will cause a burnt smell. 

Is It Normal For White Smoke To Come Out On Startup?

White smoke is just nothing if it is just a thin vapor. It can cause just a typical result of condensation buildup inside the exhaust system. 

The white smoke will disappear quickly. However, thicker smoke might be a big problem, and it can cause an engine that is burning coolant.

What To Do When Your Car Has White Smoke On Startup?

To fix the white smoke from the exhaust problem on startup and prevent the problem from happening again, you can fix the issue at your home. But, of course, you can bring your vehicle to a mechanic also.

1. Inspect The Intake Gasket

A gasket inside your vehicle seals and then manifolds to the head. The maniform and the gasket will distribute the mixture of the air and fuel within the vehicle and transport the necessary cooling fluid to the intake port. 

These ports are in the cylinder heads. To fix this, remove the intake manifold. 

2. Check The Head Gasket

Your damaged head gasket can cause white smoke from the exhaust of your vehicle on startup. If your head gasket is working fine, move to the head gasket. 

This part will seal the cylinder head and ensure that the coolant will not leak and get into the cylinder. However, if there are damages or leaks in the liquid lines that will transport the coolant and the oil, this part can cause the coolant to leak in the chamber and create white smoke from the exhaust on startup.

3. Cracks In The Cylinder Head

The cylinder head is accessible to break if your vehicle is overheating and there is excess friction between the metal parts. You will also need to keep it in a safe and working condition since it connects the engine block and hits the head gasket. It will form a transportation bridge between the two parts. 

Can Spark Plugs Cause White Smoke?

No. Spark plugs do not cause white smoke. The reasons are stated above for the white smoke coming out of your exhaust.


In summary, people complain about having white smoke on startup and then disappear. Even if it will disappear, it is essential to have your vehicle checked by an expert. 

There are plenty of reasons for this. Find the sole reason and then have it fixed.



Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more