DIY PCV Valve Replacement

It is recommended that positive crankcase ventilation or PCV valve replacement is done every 30,000 to 60,000 miles. The PCV valve is a piece of plastic tubing that is an essential component of your car’s emission-control system. It is a government required component that you may be tempted to remove or bypass if it is faulty, but that is not recommended. A faulty or clogged PCV valve will cause a variety of issues including poor acceleration, poor gas mileage and poor emissions. Replacing the PCV valve is a fairly simple task. Here's what you'll need:

Tools and Materials

  • New PCV Valve
  • PCV Valve rubber hose
  • Needle Nose Pliers
  • Small Amount of Motor Oil (optional)

Step 1 – Preparation

Open the hood of your car and locate the faulty PCV valve. It will be plugged into the top of your engine's crankcase. You should be able to easily recognize the valve. It will have a rubber hose sticking out of the top. If you are having trouble finding the valve, your car owner's manual should have a diagram of the location. Don’t attempt to work on the car when the engine is hot.

Step 2 – Removing the PCV Valve

The first step in replacing the PCV valve is to remove the rubber hose that is attached to it. You should be able to simply grab this hose and pull it off the valve. If it is held by any clamps, remove those first and then remove the old hose. Set these parts aside as you might need them again.

If the PCV valve is difficult to reach with your fingers, take the needle nose pliers, grab the valve by the top knob where the hose attaches and simply pull the valve out. There is no need to save the old valve.

Step 3 – Installing the New PCV Valve

Take the new PCV valve out of the package. If the valve came with a new hose, attach the hose to the valve now. It will be much easier to do now instead of after the new PCV valve is installed. If the replacement parts did not include a new hose, use the old hose you just removed.

Take the PCV valve assembly and insert it back into the engine block. Orient the valve and hose assembly in the same direction the old assembly was in and reconnect the valve hose at the other end. Sometimes a thin coating of motor oil around the bottom of the valve will make the installation go more smoothly if you are having trouble inserting it.

Step 4 – Finishing the Installation

Lastly, remove any tools and parts from the engine compartment and start the engine. Listen for any possible air leaks in the new PCV valve assembly you just replaced. There shouldn't be any issues, but it's not a bad routine to get into after any repairs that involve air flow to or from your engine block.

And that's all there is to this very simple, yet very important repair to your car's emission control system.