Answer: Sometimes you will only see the smoke when you start your car or when you stop at a traffic light or stop sign. The smoke may be accompanied by engine idling problems. This is a problem that should not be ignored as it may be an indication of a serious and dangerous condition. The cause of the problem is best identified by the color, smell, and amount of smoke. Pay close attention to this. This problem may develop over time and the amount of smoke indicates the seriousness of the problem. The probable causes are: 1. If the smoke has an oily smell, there is an oil leak. 2. If the smoke is white, there is probably an anti-freeze (engine coolant) leak. 3. If the smoke is blue or black and has a strong acrid smell, there is probably an electrical problem, and wires are burning.

Answer: The engine of a vehicle needs oil for lubrication thus enabling smooth functioning. Engine oil earlier were monogrades (single viscosity type) but today they are of a much more complex nature. As engines can be either two stroke and four stroke there are two types for either engine.

Answer:
1. To provide a thia film of oil between moving parts to reduce friction and metal to metal contact.

2. To remove heat generated in an engine during its Operations to keep internal parts cool.

3. To reduce wear of metallic parts like Cylinder rings value gears bearings.

4. To keep the engine clear from deposits, sludge etc.

5. To control corrosion and rusting of various parts.