The PCV system is relatively easy to test and work on. The components in the PCV system are inexpensive parts.
Symptoms and signs to look for in a failing PCV system are:
The check engine/service engine light can illuminate from a plugged, failing or restricted PCV system. It regulates air flow, if not working properly, it can cause a diagnostic trouble code like an engine lean condition code or may signal a mass air flow sensor or oxygen sensor code. If the crankcase is not relieved of excessive pressure, the pressure can cause damage to seals and gaskets, characterized by oil leaks.
Excess air flow through the PCV system can cause oil consumption, which can be seen by an oil decrease in between oil changes, without any obvious oil leak. The air filter element might also be impregnated with oil from the blow-by. A PCV valve can stick or fail to work properly and the inlet/outlet hoses can deteriorate by getting hard, crispy, and crack with age or soft/swollen with oil contamination, along with the mounting gaskets and seals splitting or cracking and allowing an oil leak. A PCV system needs to be kept sealed to have proper operation. A leak in the system can cause any of those symptoms. Operating a vehicle with proper oil level and pressure reduces the risk of internal engine damage.
We recommend the PCV system be inspected by a trusted repair facility. As regular maintenance, a PCV system should be inspected and operation should be checked annually.