Diesel engines emit serious blue smoke.

There are many reasons why the engine emits blue smoke, as follows:

1. Motor vehicle air filter is blocked.

2. There is too much lubricant in the oil pan at the bottom of the engine.

3. The engine is under low load for a long time.

4. The piston ring in the engine is stuck or excessively worn.

5. The steel pad, piston and air cushion inside the engine are damaged.