What is a car PCV valve?
1 Answers
A car PCV (Positive Crankcase Ventilation) valve is a crankcase forced ventilation valve. Its function is to discharge excess exhaust gases from the crankcase into the intake manifold, allowing them to enter the combustion chamber for burning, thereby reducing air pollution. If the PCV valve becomes clogged, blow-by gases cannot be drawn into the intake manifold, causing increased crankcase pressure and potentially leading to oil leaks. Below is more detailed information: 1. Function of the PCV valve: It directs gases from the crankcase into the intake manifold via the PCV valve. A small amount of air also enters the intake manifold directly from the air filter through the PCV valve. This prevents issues such as throttle icing, incomplete combustion, and worsened emissions. Additionally, it prevents blow-by gases from entering the atmosphere and helps avoid oil deterioration. 2. Working principle: The PCV valve is a metering control valve installed between the crankcase ventilation system and the intake system. It is controlled by vacuum pressure and regulates the flow of oil vapor from the crankcase ventilation system into the intake system. The flow rate is higher during high-speed engine operation compared to low-speed operation. Furthermore, the PCV valve should cut off ventilation in the event of engine backfire to prevent crankcase explosions.
