What are the causes of high crankcase pressure in an engine?

[CoreyLee]

The causes of high crankcase pressure in an engine are: 1. Blockage in the crankcase ventilation line or PCV valve; 2. Combustion exhaust gases entering the crankcase through piston rings and valve guides. The ventilation methods for the crankcase include natural ventilation and forced ventilation. To prevent excessive crankcase pressure, extend the service life of engine oil, reduce component wear and corrosion, and prevent engine oil leakage, crankcase ventilation must be implemented. The functions of the engine crankcase ventilation system are: 1. To prevent engine oil deterioration and reduce wear and corrosion of engine components; 2. To prevent leakage from the crankshaft oil seal and crankcase gasket, which could cause oil to seep out from these areas; 3. To recirculate gases that have entered the crankcase back into the combustion chamber for burning, thereby preventing the release of various oil vapors into the atmosphere.