Remove PCV hose from PCV valve.
Run engine at idle.
Place your finger over the end of the PCV valve to check for vacuum. If there is no vacuum, check for clogged valve. Replace as necessary.
Reconnect PCV hose to PCV valve.
Check PCV hoses for connection, leakage, clog and deterioration. Replace as necessary.
NOTE: If engine is idling rough, this may be caused by a clogged PCV valve or plugged hoses; therefore, never adjust idle speed without first checking PCV valve and hoses.
WARNING: An engine which is operated without any crankcase ventilation can be damaged. Therefore, it is important to replace the PCV valve at intervals shown in MAINTENANCE AND WARRANTY INFORMATION. Periodically inspect the hoses and clamps and replace any showing signs of deterioration.