What are the symptoms of a faulty car PCV valve?

[SanEliana]

PCV valve damage can cause phenomena such as white smoke emitting from the exhaust pipe, accelerated wear, and unstable idle. In severe cases, it can lead to engine idle shaking, weak acceleration, excessive oil consumption, difficulty starting the car, and ultimately shortening the engine's lifespan. Here is some extended information: 1. PCV valve: The PCV valve is a metering control valve installed between the crankcase ventilation system and the intake system. The PCV is controlled by vacuum, regulating the flow of oil fumes from the crankcase ventilation system into the intake system. The flow rate is higher when the engine is running at high speed compared to low speed. Additionally, the PCV valve should cut off ventilation to prevent crankcase explosion when engine backfire occurs. 2. Judgment method: With the engine idling, clamp the pipeline between the PCV valve and the vacuum source. If the engine speed drops by 50r/min or more, it is normal. Otherwise, check if the PCV valve and pipeline are blocked. Also, pull out the PCV valve and feel if there is strong vacuum suction at the intake port, which indicates normal operation.