How to Check and Clean the PCV Valve
Car manufacturers suggest that PCV valves be cleaned or replaced after somewhere between 20,000 to 50,000 miles of driving. Consult your owner’s manual to see where the PCV valve is located on your vehicle and what the recommended service intervals are. The valve is usually replaced during scheduled tune-ups, but depending on its type and location, you may be able to check, clean, and replace it yourself. This section has instructions for doing all the jobs.
There are several ways to check whether your PCV valve is functioning properly. Pick the one that seems easiest for you. (The engine should be idling no matter which method you choose):
Method 1: Remove the PCV valve from the valve cover with the hose still attached. Then place your finger over the open end of the hose. If the valve’s working well, you will feel strong suction. Try shaking the valve. If it’s unobstructed, it should rattle. If it’s fouled, the rattle will be indistinct or non-existent.One way to check your PCV valve.
Method 2: Remove the cap from the oil filler hole on the valve cover and place a stiff piece of paper over the opening. If your PCV valve is working properly, the paper should be sucked against the hole within seconds.
If the valve doesn’t seem to be working properly, before you go to the trouble to replace it, try cleaning it to see if that makes a difference.
Clean it yourself by immersing it in carburetor cleaner. There should be no gummy deposits or discoloration on a clean valve. If your PCV valve must be replaced, buy a new valve, remove the old one, and insert the new one in its place.