PCV valve

(Positive crankcase ventilation )

The purpose of the PCV valve is to prevent unburned hydrocarbons and carbon monoxide, present in blow by gases, from being expelled into the atmosphere. This process also helps to reduce moisture and the presents of corrosive gases in the crank case ,which extends the life of you engine and engine oil by keeping it cleaner longer.

The PCV valve accomplishes this task by redirecting the the unburned gases from the crank case into the fresh air being fed to the engine, the fresh air and unburned gases mix with the fuel and are burned off when the air fuel mix combusts achieving cleaner emissions.

Testing the PCV valve

carbureted and Throttle body (TFI) models

To test the PCV valve disconnect the PCV hose from the rocker arm cover on 1991-1995 models or disconnect it from the three way connector on 1989-1990 models. Now start the engine and let it idle. Place your thumb or finger over the open end of the PCV hose to feel for a vacuum(suction). IF you don't feel a vacuum you need to check the hose for clogs or other blockages for example a sharp kink in the hose. If need be just replace the hose with a new one. Once you have established that there are no blockages in the hose turn off your engine. Now you need to find out if the valve it's self is operating properly. What you need to do now is blow air through the PCV hose. Note*Use extreme caution , make sure you do not suck any air through the hose as it contains very toxic gases that can poison you and cause you serious physical injury.When you blow air through the hose you should feel resistance if there is no resistance the PCV valve is stuck open and you need to replace it.

Multi port Fuel Injection (MFI) models

Remove your throttle cover. Pull the PCV valve out of the rocker arm cover making sure the hose stays connected to the PCV valve. Start the engine and let it idle. Cover the open end in the PCV valve with your thumb or a finger to feel for a vacuum(suction). If you don't feel a vacuum inspect the hoses an valve for clogs or blockages such as a kink in the hoses, and if need be replace the hoses and or the valve. Turn off the engine and disconnect the hose from the PCV valve. Now shake the valve and listen for a rattle, if you don't hear a rattle you need to replace the valve with a new one.

Replacing the PCV valve

1.3L & 1.6L 8 valve TFI engines

Disconnect the hose from the PCV valve then remove it from the intake manifold with a socket or open ended wrench. Weather reinstalling the old valve or installing a new valve you need to wrap Teflon sealing tape around the threads of the PVC valve. Once you have prepared the valve treads with the tape ,hand tread the valve into the intake manifold to avoid stripping the threads. Once you have it hand tight torque it down to 133-221 in.lbs.(15-25 Nm). Now reconnect the hose and your done.

1.6L 16 valve & 1.8L MFI engines

Remove the throttle cover from the engine, pull the PCV valve out of the rocker arm cover with the hose still attached. Pinch the hose clamp and disconnect the hose from the old valve. Connect the hose to the new PCV valve being sure to secure it with the hose clamp. Insert the new PCV valve into the rocker arm cover , reinstall the throttle cover and your ready to go.

Note*If you need extra help I will be posting picture as soon as it stops snowing around here.