When starting the engine a white smoke comes out

he causes of white exhaust smoke can vary; however, it is common to see white exhaust smoke when first starting a car, especially on cooler days. This is generally steam caused by condensation. As the engine warms up and the condensation dissipates the white exhaust smoke (steam) is no longer seen. If excessive white exhaust smoke is present well after the engine warms up, it is necessary to have the car inspected for possible internal coolant leaks. Indicators of an internal coolant leak include billowing white exhaust smoke accompanied by a sweet odor or a low coolant reservoir level. An internal coolant leak can also contaminate the engine oil giving it a frothy, milky appearance. Even small amounts of coolant entering the combustion chamber will produce white exhaust smoke.
One of the main causes of white exhaust smoke and coolant loss is a cracked or warped cylinder head, a cracked engine block, or head gasket failure caused by overheating. A cracked head may allow coolant to leak into one or more cylinders or into the combustion chamber of the engine. Dirty coolant, a poorly maintained cooling system, a low coolant level, or a non-functioning cooling fan can cause engine overheating. In addition, engine wear can eventually cause the gaskets to lose their capacity to seal properly allowing internal coolant loss. Intake manifold gasket and head gasket failures are two of the most common sources of internal coolant loss caused by engine wear.
Never remove the radiator cap or coolant reservoir cap while the engine is hot or running as it can cause serious injury; always allow the car to cool down completely first. Checking for a low coolant level in the reservoir is the first step in determining if coolant loss is causing the white exhaust smoke. If the coolant reservoir is at the proper level but excessive white exhaust smoke is present, a cooling system pressure check is required to determine where, if any, coolant leaks are located.

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Are you losing coolant? The white smoke may be coolant in the combustion cylinder, possibly caused by a head gasket problem. If head gasket problem, fix that first.

With idle issues, clean/check anything that has to do with idle air system. Any applicable trouble codes?

Where is the white smoke coming from? Under hood? Out tail pipe? If excessive white smoke from tail pipe, suspect a head gasket failure which in turn will fill the cooling system with exhaust pressure forcing the coolant to come out of the reservoir and resulting in an overheating problem

white smoke is an indication of coolant in the combustion chamber. I would suggest having a compression test done as there may be a gasket problem or cracked head.

If your not overheating or losing coolant, its more than likely engine oil burning. If it is coolant related, possible blown head gasket.

white smoke could be head gasket leak. but white smoke will come with warm engine. If engine is first start cold. IT's only water in exhaust system

If you have white smoke coming out of the exhaust after the car warms up then you have coolant getting into the cylinda white smoke after start up when the engine is cold is normal intill everything warms up

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It's normal for a thin white smoke to come out of the exhaust at initial start up. This is caused from moisture built up in the exhaust burning off. However if there is a continuous flow of thick white smoke it could be a blown head gasket causing coolant to burn.

Its the problem of oil.The oil is getting burned out. The vehicle is either burning oil or it is moisture in the gas chamber if you notice white smoke from the exhaust. This is a common possibility.but in some cases this white smoke is not due to oil burning.In that case   White smoke from the exhaust is a symptom of coolant entering the combustion chamber. Normally this is a sign of a blown head gasket or cracked head. And  this is not a common problem must be repaired immediately. You must STOP driving this vehicle or you will cause serious engine damage. you will have to get both this possibilities checked.
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