Positive Crankcase Ventilation: Testing and Inspection

1. Pull end of PCV valve out of valve cover. If valve rattles when shaken, proceed to step 2. If not, replace valve.
2. Disconnect vacuum hose from air cleaner and feel for vacuum at hose with engine at idle. If vacuum is felt, system is satisfactory. If no vacuum is felt, check for obstructions in PCV system or a leaking evaporative valve.
3. Disconnect evaporative hose, then cap the tee fitting and retest. If vacuum is now felt, PCV system is satisfactory. Check evaporative system. If no vacuum is felt, check for vacuum back through the system and inspect rocker cover gasket for leaks. Repair or replace components as necessary.