Why white smoke coming in car

When car blowing white smoke from exhaust system

1. Crack engine cylinder head
2. Damaged coolant reservoir tank
3. Oil leak from combustion chamber
4. Bad fuel pump,injector,common rail
5. Engine control unit error
6. 
   
   Cracked engine block                                                                                                                            when car blowing Black smoke
   
   
    Black smoke is generally produce when there is excessive amount of fuel present in cylinder with respect to air fuel ratio is not proper                                                        Air intake chocked.                                                    This reduce the air inside the cylinder this causing rich fuel mixture🚙. 
   
   
                                                                               Faulty air pressure sensor.                                A faulty or damage sensor may indicator higher air pressure into the intake manifold which cause the ECU to inject more fuel🚙.                                                                                   
   
   
                                               Cold engine.                                                             When you start the engine in cold condition the ECU inject more amount of fuel so as to heat up the engine quickly,which result in black smoke at the time of starting.🚙