Where is the PCV valve located?

The PCV valve is usually located on or near the valve cover and connected to the intake manifold by a vacuum hose; exact placement varies by vehicle.

The PCV (Positive Crankcase Ventilation) valve is a small but important part of your engine’s emissions system. Its job is to vent crankcase gases back into the intake to be burned rather than released to the atmosphere. Because engine layouts differ across makes and models, the valve’s exact spot can vary. This guide outlines the most common locations and how to identify them, so you can locate and inspect the PCV valve on your car or truck.

Common PCV valve locations

These are the typical spots you’ll encounter on most gasoline engines. Start with these areas when you’re inspecting or replacing the PCV valve.

• Valve cover mount: The PCV valve is often threaded into or grommeted into the valve cover, with a hose running to the intake manifold or throttle body.


• Intake manifold port: Some designs place the PCV valve at a dedicated port on the intake manifold; the valve cover hose connects to this port.


• Near the throttle body or air intake housing: In newer designs, the PCV valve or a PCV assembly may sit close to the throttle body inside the intake tract.


• Integrated into the valve cover or breather assembly: Certain engines use a combined breather/PCV unit mounted on the valve cover with short hoses.

If you can’t spot the valve using these layouts, consult your owner’s manual or a model-specific repair guide, since some makes relocate the PCV or use an integrated unit.

How to identify and inspect the PCV valve

Use these steps to systematically confirm whether the PCV valve is functioning and to replace it if necessary.

1. With the hood open, locate the PCV valve and the hoses connected to the suspected area (valve cover or intake manifold).


2. Inspect the valve and hoses for cracks, oil buildup, or signs of clogging; ensure all hose fittings are secure and free of leaks.


3. Remove the PCV valve from its port and gently shake it; a working valve typically rattles at room temperature. A valve that doesn’t move or moves hesitantly may be clogged or faulty.


4. Replace the valve (and any worn grommets or hoses) if it appears clogged or defective, and reinstall with a secure fit.


5. Start the engine and observe idle and performance; a good PCV valve should not cause rough idle or vacuum leaks. If symptoms persist, check for other vacuum leaks or related issues.

After replacement, monitor engine performance for signs of improvement, such as steadier idle and reduced oil consumption. If issues persist, seek professional service for a more thorough diagnostic.

Summary

In most engines, the PCV valve sits on or near the valve cover and is tied into the intake manifold via a vacuum hose. However, layouts vary by manufacturer and model, with some cars housing the PCV in the intake manifold, near the throttle body, or as part of a combined breather unit. Start with the common locations described here, follow a careful inspection and test routine, and consult your vehicle’s manual or a qualified mechanic for model-specific guidance. Keeping the PCV valve in good working order helps maintain engine efficiency and reduce emissions.

How to unclog a PCV valve?

Hold the PCV valve over a rag or paper towel and spray it liberally with the carburetor or throttle body cleaner. Make sure to spray into both ends of the valve. You might see some dark, oily residue coming out. Let the cleaner soak for a few minutes to help break down the deposits.

How to know if a PCV valve is bad?

You can tell a PCV valve is bad by observing symptoms like a check engine light, rough idling or stalling, oil leaks or high oil consumption, and unusual engine noises such as hissing or whistling. Other signs include exhaust smoke (black, blue, or white), misfires, and a potentially contaminated air filter. 
Common signs of a bad PCV valve

• Check Engine Light: A faulty PCV valve can cause an air-fuel mixture imbalance, triggering the check engine light and storing a relevant error code. 
• Rough Idle/Stalling: The engine may idle roughly or shake, or even stall, because the valve's malfunction can lead to improper air-fuel mixture. 
• Oil leaks and consumption: A stuck-open valve can cause excessive crankcase pressure, pushing oil out of gaskets and seals, or causing the engine to burn oil, leading to a low oil level. 
• Engine noise: Listen for hissing, whistling, or grunting sounds coming from the engine, which can indicate a leak in the valve or its hoses. 
• Exhaust smoke: Blue or black smoke can mean oil is getting into the combustion chamber, while white smoke might indicate oil vapor is being burned, especially at startup. 
• Misfires: An inconsistent air-fuel mixture can cause the engine to misfire, resulting in a jolting or sputtering sensation. 
• Contaminated air filter: A failing PCV system can cause oil and other contaminants to flow into the air intake, leading to a dirty or sludgy air filter. 

How to test the PCV valve
A simple way to test the valve is to perform a rattle test: 

• Remove the PCV valve. 
• Gently shake it; a good valve will have a distinct rattling sound from the internal ball bearing. 
• If it doesn't rattle, it's likely clogged and needs replacement. 

Where is the PCV valve located in a car?

The PCV (positive crankcase ventilation) valve is most commonly located on the engine's valve cover, where it's connected to a hose that runs to the intake manifold. To find it, look for a small, plastic valve on the top or side of the valve cover with a hose attached to it. Some vehicles may have it in other locations, so checking your car's repair manual is a good idea for precise placement.
 
This video shows how to locate and remove the PCV valve from a 2005 Jeep Liberty: 1mO'Reilly Auto PartsYouTube · Feb 26, 2019

• Common location: On the valve cover, at the end of a vacuum hose. 
• Visual cues: Look for a hose connected to a small valve, often near the front or back of the engine. 
• Alternative locations: In some cases, it may be found near the intake manifold or in a less accessible area, especially in certain turbocharged or older models. 
• How to confirm: Consult your vehicle's specific repair manual for the exact location. 

This video demonstrates the location of the PCV valve on a Chevrolet 5.3L Vortekch engine: 57s1ROADYouTube · Dec 8, 2018

Can you replace a PCV valve yourself?

Yes, replacing a PCV valve yourself is a feasible DIY task for most people, as it is often inexpensive and requires basic tools. The process generally involves locating the valve, disconnecting the attached hose, removing the old valve (which may twist out or pull out), and then installing the new one by reversing the steps. 
Steps for replacing a PCV valve

1. Locate the PCV valve: It's typically attached to the valve cover by a rubber hose. You may need a service manual or an online resource to find it on your specific vehicle. 
2. Disconnect the hose: Carefully pull the rubber hose off the end of the PCV valve. If it's brittle, it may be best to replace it as well to avoid damage. 
3. Remove the old valve: Depending on your vehicle, you can either twist the valve counterclockwise to unscrew it or pull it straight out of its grommet. 
4. Install the new valve: Insert or screw the new valve into the same spot. Ensure it is securely seated. 
5. Reconnect the hose: Re-attach the rubber hose to the new PCV valve. 
6. Start the engine: After you've finished, start the engine and check for any leaks around the new valve and hose connections. 

What you'll need

• New PCV valve: Make sure to get the correct one for your vehicle. 
• Basic tools: This can include a wrench or socket set, depending on how the old valve is secured. 
• Replacement parts: You may also need a new hose or grommet if the old ones are cracked or brittle. 

When to consider professional help

• If the valve is difficult to access or seems complicated to remove.
• If you are working on a vehicle with a turbocharger, as it can add extra complexity to the job, notes a Reddit post. 

Important note
If the old valve breaks apart while you're removing it, be careful to collect all the pieces. This can be a common issue, and falling pieces could cause further damage, as described in this Reddit thread.