Smoke comes from the exhaust

Smoke, water vapor, or coolant? Is it something new, or has always been there? Water, in the form of steam, is produced in the combustion process. Until the exhaust system warms up, it condenses there and creates that typical white cloud out of the tailpipe in cold weather. This is perfectly normal. If it's greenish (or orange, depending on the color of coolant you use) and has that sickly sweet smell, your engine may have a blown head gasket or worse, a crack in the cylinder block. Look for traces of that color inside the tailpipe. Also check if the coolant level is dropping without any visible leak. Bluish smoke indicates burning oil due to worn valve guides or piston rings. You may suspect that if the oil consumption is high and you don't see any external leak. But usually the telltale smoke due to oil burning gets worse, not better, when the engine warms up.