The pipeline connecting my Le Chi 0.8 throttle valve and the air cleaner always leaks oil. It's normal to have oil, but there is too much. Seek a professional answer.

Exhaust gas from the crankcase should be sucked into the intake manifold and burned in each cylinder to reduce exhaust emissions. There is something called an oil-gas separator between them. This thing is damaged, and your car is too old and has too much exhaust. This is the result, that is, it is blown up by exhaust gas again.