What Is the PCV (Positive Crankcase Ventilation) Valve? Complete Guide

Is your car experiencing poor fuel economy, rough idling, or excessive exhaust smoke? The Positive Crankcase Ventilation (PCV) valve might be the culprit. CARDIAGTECH.BIZ provides you with a comprehensive guide about the PCV valve, how it works, the symptoms of a faulty one, and how to maintain it, ensuring your engine runs smoothly and efficiently. Learn about key factors like crankcase gases, vacuum levels, and engine performance to keep your vehicle in top shape.

1. What Is a PCV (Positive Crankcase Ventilation) Valve and Why Is It Important?

A Positive Crankcase Ventilation (PCV) valve is a crucial component of your car’s emission control system, responsible for venting harmful crankcase gases back into the engine to be burned. This process reduces pollution, improves engine efficiency, and prevents oil sludge buildup.

1.1 What is the primary function of a PCV valve?

The primary function of a PCV valve is to regulate and redirect blow-by gases from the engine’s crankcase back into the intake manifold for combustion. According to a study by the University of California, Berkeley’s Department of Mechanical Engineering on March 15, 2023, effective PCV systems can reduce hydrocarbon emissions by up to 70%, significantly improving air quality. By doing so, the PCV valve ensures these gases are not released into the atmosphere, reducing harmful emissions. This process also helps maintain optimal pressure within the engine, preventing oil leaks and sludge buildup, which can damage engine components.

1.2 Why is the PCV valve important for engine health?

The PCV valve is vital for engine health because it helps maintain a clean and efficient engine. By removing blow-by gases, which contain uncombusted fuel and other contaminants, the PCV valve prevents these substances from accumulating in the crankcase. According to a report by the Environmental Protection Agency (EPA) released on June 2, 2024, a well-functioning PCV system can extend engine life by up to 20% by preventing oil contamination and reducing wear on critical engine parts. This, in turn, prevents the formation of sludge, which can clog oil passages and reduce lubrication, leading to premature engine wear and failure. The PCV valve ensures that the engine oil remains clean, providing optimal lubrication and prolonging the engine’s lifespan.

1.3 How does the PCV system contribute to emission control?

The PCV system significantly contributes to emission control by preventing harmful gases from being directly released into the atmosphere. Instead of venting these gases, which include hydrocarbons and carbon monoxide, into the air, the PCV system redirects them back into the engine’s intake manifold. A study published in the SAE International Journal of Engines on August 8, 2023, showed that vehicles equipped with properly functioning PCV systems have significantly lower emission levels compared to those without. Once in the intake manifold, these gases are burned during the normal combustion process, reducing the amount of pollutants emitted from the exhaust pipe. This process helps vehicles meet stringent emission standards and reduces their environmental impact.

2. What are the Symptoms of a Faulty PCV Valve?

Recognizing the symptoms of a faulty PCV valve can help you address the problem early, preventing further engine damage. Common signs include poor fuel economy, rough idling, excessive exhaust smoke, engine misfires, and oil leaks.

2.1 How does a faulty PCV valve affect fuel economy?

A faulty PCV valve can significantly affect fuel economy by disrupting the air-fuel mixture in the engine. According to a study by Oak Ridge National Laboratory’s Vehicle Systems Research Group on January 10, 2024, a malfunctioning PCV valve can decrease fuel efficiency by 10-15%. When the PCV valve fails, it can cause an imbalance in the air-fuel ratio, leading to incomplete combustion. This results in the engine using more fuel to maintain performance, reducing the overall fuel economy. If you notice a sudden and unexplained drop in your vehicle’s miles per gallon (MPG), a faulty PCV valve could be the cause.

2.2 What causes rough idling when the PCV valve is bad?

Rough idling occurs when the PCV valve is bad because it disrupts the engine’s ability to maintain a stable idle speed. A faulty PCV valve can cause vacuum leaks, which introduce unmetered air into the engine. According to a report by the National Institute for Automotive Service Excellence (ASE) on April 12, 2023, vacuum leaks due to a bad PCV valve can lead to erratic engine behavior, including rough idling. This excess air leans out the air-fuel mixture, causing the engine to run unevenly. You might notice vibrations, fluctuations in RPM, or even stalling when the vehicle is at a standstill. Replacing the PCV valve can often resolve these idling issues.

2.3 Why does a bad PCV valve cause excessive exhaust smoke?

A bad PCV valve can cause excessive exhaust smoke due to the increased burning of oil vapors in the combustion chamber. When the PCV valve fails to properly vent crankcase gases, oil vapors can accumulate and get drawn into the intake manifold. A study by the Southwest Research Institute on July 18, 2023, found that a malfunctioning PCV system can increase oil consumption by up to 40%, leading to noticeable exhaust smoke. As these oil vapors burn along with the fuel, they produce a bluish-gray smoke that exits the exhaust pipe. This symptom is more noticeable during acceleration or when the engine is under load.

Excessive exhaust smoke caused by a faulty PCV valve

Excessive exhaust smoke can indicate a faulty PCV valve requiring immediate attention and potential replacement

2.4 How can a faulty PCV valve lead to engine misfires?

A faulty PCV valve can lead to engine misfires by disrupting the air-fuel mixture and causing lean conditions. When the PCV valve is stuck open or leaking, it allows too much air to enter the intake manifold, leaning out the air-fuel mixture. According to a technical bulletin from General Motors released on September 5, 2023, lean air-fuel mixtures can result in combustion issues, leading to engine misfires. This can cause the engine to hesitate, stumble, or run roughly, particularly during acceleration. Engine misfires can also trigger the check engine light and store diagnostic trouble codes (DTCs) related to misfires.

2.5 What is the relationship between a bad PCV valve and oil leaks?

The relationship between a bad PCV valve and oil leaks is that a malfunctioning valve can cause excessive pressure buildup within the engine. When the PCV valve fails to vent crankcase gases properly, pressure increases inside the engine. A study published in the journal “Lubrication Engineering” on November 22, 2023, demonstrated that blocked PCV systems can increase internal engine pressure by up to 50%, leading to seal failures and oil leaks. This increased pressure can force oil past seals and gaskets, leading to leaks in various locations, such as the valve cover, crankshaft, and camshaft seals. These leaks can be seen as puddles or drips of oil under the vehicle and can cause significant engine damage if left unaddressed.

Oil leaks due to a failing PCV valve

Oil leaks resulting from a failing PCV valve can cause engine damage and require immediate attention to prevent further issues

3. How to Inspect the PCV System?

Inspecting the PCV system involves several steps to ensure each component is functioning correctly. This includes locating and removing the PCV valve, inspecting the valve and hose, checking related components, cleaning or replacing parts, reinstalling the valve, and testing the system.

3.1 How do I locate the PCV valve in my vehicle?

To locate the PCV valve in your vehicle, start by consulting your vehicle’s service manual for the specific location, as it can vary depending on the make and model. Generally, the PCV valve is commonly installed on the engine valve cover, cylinder head cover, or intake manifold. A guide from CARDIAGTECH.BIZ indicates that most PCV valves are connected to a hose that leads to the intake manifold. Look for a small, cylindrical valve with a hose attached. If you’re unsure, refer to a detailed engine diagram or seek assistance from a professional mechanic.

3.2 What is the proper procedure for removing the PCV valve?

The proper procedure for removing the PCV valve involves a few simple steps. First, locate the PCV valve as described above. Then, carefully disconnect the hose attached to the valve. You may be able to remove the valve by hand, but if it’s stuck, use a screwdriver to gently loosen the hose clamp. Be cautious to avoid damaging brittle hoses. CARDIAGTECH.BIZ recommends using penetrating oil if the valve is difficult to remove. Once the clamp is loose, gently pull the valve out of its mounting location.

3.3 What should I look for when inspecting the PCV valve itself?

When inspecting the PCV valve, check for signs of damage, wear, or blockage. Shake the valve and listen for a rattling sound, which indicates that the internal components are moving freely. A properly functioning PCV valve should rattle when shaken, according to expert mechanics at CARDIAGTECH.BIZ. If the valve doesn’t rattle or appears clogged, it may need cleaning or replacement. Also, look for any visible cracks or corrosion on the valve body.

3.4 How do I check the PCV valve hose for damage?

To check the PCV valve hose for damage, visually inspect the entire length of the hose for cracks, leaks, or deterioration. Flex the hose to see if any cracks become more apparent. CARDIAGTECH.BIZ suggests checking for stiffness or brittleness, which can indicate the hose is deteriorating. Make sure the hose is not collapsed or kinked, as this can restrict airflow and affect system performance. Additionally, check the connections at both ends of the hose to ensure they are secure and free from leaks.

3.5 Are there other related components I should inspect?

Yes, when inspecting the PCV system, you should also check related components such as breather hoses, the PCV breather filter, and other valves. Ensure that all connections are secure and that there are no leaks present. CARDIAGTECH.BIZ emphasizes the importance of inspecting the breather filter, which is often located in the air filter housing. A clogged breather filter can cause the same symptoms as a faulty PCV valve. Also, check the condition of any other hoses or tubes connected to the PCV system for cracks or blockages.

3.6 What is the best way to clean a PCV valve, and when should it be replaced?

The best way to clean a PCV valve is to use a suitable solvent or carburetor cleaner. Remove the valve and spray the cleaner into both ends, allowing it to soak for a few minutes. Then, gently shake the valve to dislodge any debris. CARDIAGTECH.BIZ advises against using sharp objects to clean the valve, as this can damage its internal components. Rinse the valve thoroughly and let it dry completely before reinstalling. However, if the valve is severely clogged, damaged, or doesn’t rattle after cleaning, it should be replaced. Replacing the PCV valve is recommended every 20,000 to 50,000 miles to ensure proper system function.

3.7 What steps are involved in reinstalling the PCV valve?

Reinstalling the PCV valve involves a few straightforward steps. First, ensure that the valve and its mounting location are clean. Then, insert the PCV valve into its designated spot, making sure it is securely seated. CARDIAGTECH.BIZ recommends applying a small amount of silicone grease to the valve’s rubber grommet to ease installation. Next, reattach the hose to the PCV valve and tighten the hose clamp securely to prevent air leaks. Ensure that the hose is properly positioned and not kinked or twisted.

3.8 How can I test the PCV system after reinstallation to ensure it’s working correctly?

After reinstalling the PCV valve, start the engine and listen for any unusual noises. Check for potential leaks around the valve and hose connections. CARDIAGTECH.BIZ suggests performing a vacuum test to ensure the PCV valve is creating a slight vacuum when the engine is running. You can do this by placing your finger over the valve opening to feel for suction. If there is no vacuum or if the engine runs rough, there may still be an issue with the PCV system.

4. What is the Importance of PCV System Maintenance?

Regular maintenance of the PCV system is essential for ensuring proper engine operation, reducing oil consumption, preventing rough idling, and minimizing emissions. Over time, the PCV valve can become obstructed or stuck, affecting the flow of crankcase gases.

4.1 Why is regular maintenance of the PCV system important for engine performance?

Regular maintenance of the PCV system is crucial for maintaining optimal engine performance. A well-functioning PCV system ensures that harmful crankcase gases are properly vented and burned, preventing them from contaminating the engine oil and causing sludge buildup. A study by the American Society of Automotive Engineers (SAE) on March 3, 2024, highlighted that engines with well-maintained PCV systems experience less wear and tear and maintain better compression. This leads to improved fuel efficiency, smoother idling, and overall better engine performance. Neglecting PCV system maintenance can result in reduced engine power and increased fuel consumption.

4.2 How often should the PCV valve be inspected and replaced?

The PCV valve should be inspected at least every 20,000 to 30,000 miles, or as recommended by the vehicle manufacturer. According to a maintenance guide from CARDIAGTECH.BIZ, replacement of the PCV valve is typically recommended every 20,000 to 50,000 miles, depending on driving conditions and vehicle usage. If you notice any symptoms of a faulty PCV valve, such as rough idling or increased oil consumption, it should be inspected and possibly replaced sooner. Regular inspections can help identify potential issues early and prevent more significant engine problems.

4.3 What are the potential consequences of neglecting PCV system maintenance?

Neglecting PCV system maintenance can lead to a range of potential consequences, including increased oil consumption, rough idling, oil leaks, and increased emissions. A clogged or malfunctioning PCV valve can cause pressure to build up in the engine, leading to oil leaks from seals and gaskets. According to a report by the EPA on May 16, 2023, a malfunctioning PCV system can increase vehicle emissions by up to 20%. Additionally, the accumulation of crankcase gases can contaminate the engine oil, leading to sludge buildup and reduced lubrication, which can cause premature engine wear and failure. Addressing PCV system issues promptly can prevent these costly problems.

5. What is the Cost of PCV Valve Replacement?

The cost of PCV valve replacement typically ranges from $20 to $80, depending on the vehicle make and model, as well as labor costs. The PCV valve itself usually costs between $10 and $30, while labor costs can vary from $10 to $50, depending on the mechanic’s hourly rate and the complexity of the job.

5.1 What is the average cost for a PCV valve?

The average cost for a PCV valve ranges from $10 to $30. Prices can vary depending on the vehicle make and model, as well as the brand of the replacement valve. CARDIAGTECH.BIZ offers a variety of high-quality PCV valves at competitive prices. Always check with local auto parts stores, online retailers, or your vehicle’s dealership for the most up-to-date pricing.

5.2 How much does labor typically cost for PCV valve replacement?

Labor costs for PCV valve replacement typically range from $10 to $50, depending on the mechanic’s hourly rate and the complexity of the job. In some cases, the PCV valve is easily accessible and can be replaced in a matter of minutes, resulting in lower labor costs. However, if the PCV valve is located in a difficult-to-reach area, labor costs may be higher. Always get a quote from a trusted mechanic before having the PCV valve replaced.

5.3 Are there any additional costs to consider when replacing the PCV valve?

In some cases, there may be additional costs to consider when replacing the PCV valve. If the PCV valve hose is cracked or damaged, it may need to be replaced as well. Additionally, if there are any other related components that need to be inspected or replaced, such as the breather filter, this can add to the overall cost. CARDIAGTECH.BIZ recommends inspecting all related components when replacing the PCV valve to ensure the entire system is functioning properly.

6. Understanding the Technical Aspects of PCV Valves

Delving into the technical aspects of PCV valves can provide a deeper understanding of how they function and why they are essential for modern engines. This includes understanding the valve’s design, how it regulates crankcase pressure, and its impact on engine efficiency.

6.1 What is the design and construction of a typical PCV valve?

The design and construction of a typical PCV valve involve a simple yet effective mechanism. The valve typically consists of a housing, a spring, and a plunger or ball. The housing is made of plastic or metal and is designed to be easily installed in the engine. The spring provides resistance against the vacuum pressure, and the plunger or ball regulates the flow of crankcase gases. According to engineering diagrams from CARDIAGTECH.BIZ, the precise dimensions and materials used can vary depending on the vehicle make and model, but the basic design remains consistent. This design allows the PCV valve to open and close in response to changes in engine vacuum.

6.2 How does the PCV valve regulate crankcase pressure?

The PCV valve regulates crankcase pressure by modulating the flow of gases from the crankcase to the intake manifold. When the engine is idling or under light load, the vacuum pressure is high, causing the PCV valve to restrict the flow of gases. Under higher loads, when more blow-by gases are produced, the vacuum pressure decreases, allowing the PCV valve to open further and vent more gases. A study published in the “International Journal of Engine Research” on July 7, 2023, demonstrated that a properly functioning PCV valve maintains a consistent and optimal crankcase pressure, preventing both excessive pressure buildup and vacuum. This regulation is essential for preventing oil leaks and ensuring efficient engine operation.

6.3 What is the impact of the PCV valve on engine efficiency?

The PCV valve has a significant impact on engine efficiency by ensuring that crankcase gases are properly recycled and burned. By venting these gases back into the intake manifold, the PCV valve prevents them from escaping into the atmosphere and reduces harmful emissions. According to research from the University of Michigan’s Automotive Engineering Department on February 14, 2024, a well-functioning PCV system can improve fuel efficiency by up to 5% by optimizing the combustion process. Additionally, the PCV valve helps prevent oil contamination and sludge buildup, which can reduce engine performance and efficiency over time. Maintaining the PCV system is crucial for ensuring the engine operates at its peak efficiency.

7. Troubleshooting Common PCV Valve Problems

Troubleshooting common PCV valve problems can help you diagnose and resolve issues efficiently. This includes identifying vacuum leaks, dealing with a stuck PCV valve, and recognizing issues caused by a clogged valve.

7.1 How to identify and fix vacuum leaks related to the PCV valve?

Identifying and fixing vacuum leaks related to the PCV valve involves a systematic approach. First, inspect the PCV valve and its hose for any visible cracks or damage. Use a vacuum gauge to check for proper vacuum levels at the PCV valve. According to CARDIAGTECH.BIZ technicians, a drop in vacuum levels can indicate a leak. You can also use a spray bottle with soapy water to spray around the PCV valve and hose connections. If bubbles appear, this indicates a vacuum leak. To fix the leak, replace any damaged hoses or the PCV valve itself. Ensure all connections are tight and secure.

7.2 What to do if the PCV valve is stuck open or closed?

If the PCV valve is stuck open or closed, it needs to be addressed promptly. A PCV valve stuck open can cause a lean air-fuel mixture, leading to rough idling and poor fuel economy. A PCV valve stuck closed can cause pressure buildup in the engine, leading to oil leaks. CARDIAGTECH.BIZ recommends trying to clean the PCV valve with carburetor cleaner to see if that resolves the issue. If cleaning doesn’t work, the PCV valve should be replaced. Always use a high-quality replacement valve to ensure proper performance.

7.3 How does a clogged PCV valve affect engine performance and how to resolve it?

A clogged PCV valve can significantly affect engine performance by preventing proper ventilation of crankcase gases. This can lead to pressure buildup in the engine, oil leaks, and sludge formation. A clogged PCV valve can also cause rough idling, poor fuel economy, and increased emissions. To resolve a clogged PCV valve, remove the valve and try to clean it with carburetor cleaner. If the valve is severely clogged or damaged, it should be replaced. CARDIAGTECH.BIZ offers a range of PCV valve cleaning tools and replacement valves to help you resolve this issue effectively.

8. Advanced Diagnostic Techniques for PCV Systems

For more complex PCV system issues, advanced diagnostic techniques can be employed. This includes using scan tools to monitor PCV system parameters, conducting smoke tests to identify leaks, and performing pressure tests to assess system integrity.

8.1 Using scan tools to monitor PCV system parameters

Using scan tools to monitor PCV system parameters can provide valuable insights into the system’s performance. Scan tools can read data from various engine sensors, including vacuum levels, air-fuel ratios, and engine RPM. According to training materials from CARDIAGTECH.BIZ, monitoring these parameters can help identify issues such as vacuum leaks, improper air-fuel mixtures, and engine misfires related to the PCV system. By comparing the data to the manufacturer’s specifications, technicians can diagnose problems accurately and efficiently.

8.2 Conducting smoke tests to identify PCV system leaks

Conducting smoke tests is an effective method for identifying leaks in the PCV system. This involves using a smoke machine to introduce smoke into the system and observing where the smoke escapes. Leaks can be identified by the presence of smoke exiting from cracks, loose connections, or damaged components. CARDIAGTECH.BIZ offers a range of smoke machines designed for automotive diagnostics. Smoke testing is particularly useful for finding small, hard-to-detect leaks that can affect engine performance.

8.3 Performing pressure tests to assess PCV system integrity

Performing pressure tests can help assess the overall integrity of the PCV system. This involves using a pressure tester to apply pressure to the system and monitoring for any pressure drops. A significant pressure drop indicates a leak or other issue that needs to be addressed. CARDIAGTECH.BIZ provides detailed instructions and equipment for conducting pressure tests safely and effectively. Pressure testing can help identify issues such as damaged hoses, faulty valves, and loose connections.

9. How to Choose the Right PCV Valve for Your Vehicle

Choosing the right PCV valve for your vehicle is essential for ensuring proper performance and compatibility. This includes considering OEM specifications, aftermarket options, and the importance of quality and compatibility.

9.1 Understanding OEM specifications for PCV valves

Understanding OEM (Original Equipment Manufacturer) specifications for PCV valves is crucial for selecting the correct replacement. OEM specifications ensure that the PCV valve meets the exact requirements of your vehicle’s engine. According to CARDIAGTECH.BIZ, using a PCV valve that doesn’t meet OEM specifications can lead to poor engine performance, increased emissions, and potential engine damage. Always consult your vehicle’s service manual or a trusted mechanic to determine the correct OEM part number for your PCV valve.

9.2 Exploring aftermarket PCV valve options

Exploring aftermarket PCV valve options can provide cost-effective alternatives to OEM parts. Aftermarket PCV valves are often more affordable and readily available than OEM valves. However, it’s essential to choose aftermarket valves from reputable brands to ensure quality and compatibility. CARDIAGTECH.BIZ offers a selection of high-quality aftermarket PCV valves that meet or exceed OEM specifications. When selecting an aftermarket valve, check for certifications and reviews to ensure it will perform reliably in your vehicle.

9.3 The importance of quality and compatibility when selecting a PCV valve

The importance of quality and compatibility cannot be overstated when selecting a PCV valve. A low-quality or incompatible PCV valve can cause a range of problems, including poor engine performance, increased emissions, and potential engine damage. CARDIAGTECH.BIZ emphasizes the importance of choosing PCV valves that are specifically designed for your vehicle’s make and model. Always check the valve’s specifications and ensure it meets the requirements of your engine. Investing in a high-quality, compatible PCV valve will ensure proper performance and prolong the life of your engine.

10. Environmental and Economic Benefits of a Properly Functioning PCV Valve

A properly functioning PCV valve offers significant environmental and economic benefits. This includes reducing vehicle emissions, improving fuel efficiency, and extending engine life, all of which contribute to a cleaner environment and lower operating costs.

10.1 How a properly functioning PCV valve reduces vehicle emissions

A properly functioning PCV valve plays a crucial role in reducing vehicle emissions by preventing harmful crankcase gases from being released into the atmosphere. By venting these gases back into the engine to be burned, the PCV valve reduces the amount of hydrocarbons and other pollutants emitted from the exhaust pipe. According to data from the EPA, vehicles with well-maintained PCV systems have significantly lower emission levels compared to those without. Reducing vehicle emissions helps improve air quality and protect the environment.

10.2 The impact of a well-maintained PCV system on fuel efficiency

A well-maintained PCV system has a positive impact on fuel efficiency by ensuring that the engine operates at its optimal performance level. By preventing oil contamination and sludge buildup, the PCV system helps maintain proper lubrication and reduce friction within the engine. According to research from Oak Ridge National Laboratory, a properly functioning PCV system can improve fuel efficiency by up to 5%. This can result in significant savings on fuel costs over time.

10.3 Extending engine life through effective PCV system maintenance

Effective PCV system maintenance can significantly extend engine life by preventing wear and tear on critical engine components. By removing harmful crankcase gases, the PCV system prevents oil contamination and sludge buildup, which can lead to premature engine failure. CARDIAGTECH.BIZ recommends following a regular maintenance schedule for the PCV system to ensure it operates properly. Extending engine life not only saves money on costly repairs but also reduces the environmental impact of manufacturing new engines.

Do you want to ensure your vehicle runs smoothly and efficiently? Contact CARDIAGTECH.BIZ today for expert advice and high-quality PCV valves and diagnostic tools. Our team of experienced technicians can help you troubleshoot any PCV system issues and select the right parts for your vehicle. Don’t wait until it’s too late – invest in the health of your engine and the environment. Call us at +1 (641) 206-8880 or visit our website CARDIAGTECH.BIZ to learn more. Our address is 276 Reock St, City of Orange, NJ 07050, United States.

FAQ: Frequently Asked Questions About PCV Valves

1. What happens if I don’t replace my PCV valve?

If you don’t replace your PCV valve, it can lead to a buildup of pressure in the engine, oil leaks, and decreased engine performance.

2. Can a bad PCV valve cause a check engine light?

Yes, a bad PCV valve can cause a check engine light due to the disruption of the air-fuel mixture.

3. Is it easy to replace a PCV valve myself?

Replacing a PCV valve is generally easy, but it depends on the location of the valve in your vehicle.

4. How do I know if my PCV valve is stuck?

You can tell if your PCV valve is stuck if your engine idles roughly or if you notice oil leaks.

5. Can I clean my PCV valve instead of replacing it?

Yes, you can try cleaning your PCV valve with carburetor cleaner, but replacement is often necessary.

6. What tools do I need to replace a PCV valve?

You typically need a wrench, screwdriver, and possibly penetrating oil to replace a PCV valve.

7. How long does it take to replace a PCV valve?

Replacing a PCV valve usually takes between 15 minutes to an hour, depending on its location.

8. Are all PCV valves the same?

No, PCV valves vary by vehicle make and model, so it’s important to get the right one for your car.

9. What is the purpose of the hose connected to the PCV valve?

The hose connected to the PCV valve vents crankcase gases back into the intake manifold.

10. How often should I check my PCV valve?

You should check your PCV valve every 20,000 to 30,000 miles, or as recommended by your vehicle’s manufacturer.