The most common failure of the PCV valve is that it remains blocked, producing a series of anomalies in the engine:
Engine starts hard
rough idle
Engine suddenly dies at IDLE
Presence of engine oil in the air filter
Oil leaks in the engine
High idle RPM
Changing the PCV valve is very simple but you must first confirm that it is blocked, the blockage can be intermittent so you can confuse a PCV valve with this type of damage.
Every 2 years it is recommended to change the PCV valve to avoid engine malfunction, its cost is low: less than $10.00 (Ten Dollars).