If you don't feel vacuum at your fingertip, check the valve and hoses for gunk obstructing airflow.If you notice a bigger rpm drop and the engine idle smooths out, your PCV valve might be stuck open.If not, look for a blocked or restricted vacuum hose or valve. Idle speed will drop between 40 to 80 RPMs and then rise back to normal.Another way to test for vacuum is to pinch or block the vacuum hose connected to the PCV valve.Consult your vehicle repair manual, if necessary. If resistance is infinite, the coil is open and the valve needs to be replaced. If your PCV valve is electrically heated, check the heater coil using an ohmmeter.Even if the valve rattles, if your engine is experiencing one or more of the bad PCV valve symptoms described above, it's a good idea to replace the valve. If you don't, it is time to replace the valve. Once you remove the valve, shake it with your hand. Most PCV valves contain a spring-loaded device.Some car manufacturers recommend replacing the filter every 30,000 miles or so.

On some engines, you'll find a mesh filter underneath the valve.

Regardless of the type of PCV valve your engine uses, always buy a quality brand valve, since it's more likely to have a more precise calibration for your specific engine model. Other valves incorporate heating elements and cost more.

Many engine models use a simple, inexpensive valve, and many car owners just replace it every service interval.

Or, simply replace those components along with the PCV valve. If you find the hoses filled with slime, clean them with PCV solvent or lacquer thinner and replace the valve.

Carefully disconnect the valve and any system hoses and visually inspect them.

Replace one or more of these components as necessary. Rubber components like grommets, O-rings, and hoses swell and turn hard and brittle after constant exposure to high temperatures. Luckily, once you locate the valve, it doesn't take much to check the system.

What does a egv valve do