Light white smoke coming from exhaust - BMW Motorcycles

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.

What is year--make--model?
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?

http://www.carsdirect.com/car-repair/causes-of-white-exhaust-smoke


Causes of White Exhaust Smoke

The white smoke you are seeing is steam. From your description, sounds like you have coolent seeping into the combustion chamber, mixing with your fuel/air, and exiting out through your exhaust as steam. 1, blown head gasket. 2. cracked head or block, 3, warped head due to overheating. Most common is #1.

Is it a lot of white smoke? White/Gray Smoke: White exhaust smoke is an indication that coolant is burning in the combustion chamber. These are possible causes:
Cylinder Head: A crack in the cylinder head (around the coolant jacket) will cause coolant to enter the combustion chamber.


Although for some cars white smoke is normal, as long as it is not super excessive.

Dear Sir,
As you said engine light is on and misfire with white smoke, it clearly symptom of poor ignition spark may cause of any wire got disconnected or spark plug faulty.
white smoke comes only in case no spark at spark plug and un burn fuel throwing from silencer. check wire and spark plug if any issue let me know. thanks.

Yogesh

white smoke out off exhaust is coolant getting into cyl like a bad head gasket to much fuel would be black smoke

Hi dluv, what color is the smoke coming from your exhaust? Is it black,blue, grey or white?