What cause car to smoke?

Answer 1

It depends on the type of "smoke".

1. Blue-Grey smoke is typically particles of unburned oil. If an engine is doing that you should see the engine using oil. Watch the dipstick and don't let the engine run out. Rarely the condition can be caused by a leaky vacuum modulator in the transmission, but that's only for older transmissions that actually have a vacuum modulator. Engines can burn oil when: 1) a valve stem seal fails, resulting in oil being sucked into the intake, 2) piston rings wear, allowing oil to leak past and build up in the combustion chamber, 3) Piston ring grooves build up with sludge and/or carbon, causing the rings to be trapped and not flex to do their job, 4) cracked or broken piston, 5) scored cylinder wall. When an engine burns oil it is almost always caused by poor maintenance.

2. Black smoke is the result of an engine that is getting too much fuel. Typically that is caused by a sticking injector, or in the case of a carburated engine, it can be a choke that is sticking or not adjusted properly.

3. White smoke is usually just steam. When gasoline burns it is changed to carbon dioxide and water vapor. You cannot see the carbon dioxide, but the water vapor cools as it passes through a cool exhaust system (cold winter mornings) and for the first few minutes the cooled water vapor will look like smoke from the vehicle exhaust.

Answer 2

the dirt emitted through the gas being used up by the car for it to accelerate its speed and make it run.