What are the causes of poor crankcase ventilation?
2 Answers
The causes of poor crankcase ventilation: 1. One-way valve blockage: During engine idling, ventilation relies on small holes at the valve end, causing the ventilation system to fail. 2. Spring force failure: The one-way valve cannot open during operation, making the ventilation unsuitable for the engine's working conditions. 3. The one-way valve is installed backward or missing, causing the ventilation device to fail. This affects the air-fuel ratio of the mixture in the intake pipe, leading to abnormal engine operation (especially no idling) or even causing oil and gas to spray out from the oil filler opening and oil leakage at related joints. 4. Improper installation: During maintenance, the sealing gasket on the bent pipe joint of the crankcase ventilation device is missing or incorrectly positioned, causing the tail end of the bent pipe joint to be too close to or even in contact with the oil baffle plate, leading to blockage and failure of the crankcase ventilation system.
I've been driving for many years, and poor crankcase ventilation is quite common. The main reasons include a clogged PCV valve, sludge or dust accumulation in the ventilation holes blocking airflow, aging or cracked ventilation pipes or loose connections causing leaks, internal engine wear such as piston ring blow-by allowing excessive exhaust gases into the crankcase, and improper maintenance like expired engine oil leading to sediment blockages. These issues aren't just simple—they can also cause oil thinning, engine idle vibration, or excessive emissions, affecting overall performance. I recommend regularly checking the system, especially inspecting the PCV valve and pipes during oil changes, as prevention is much easier than repairs. Try cleaning the valve yourself with a specialized cleaner to avoid costly hardware upgrades, and keeping the ventilation smooth will extend the engine's lifespan.
