Honda Accord PCV Valve Symptoms (9 Things To Be Aware Of)

The PCV (Positive Crankcase Ventilation) valve is a pivotal component in most internal combustion engines, including those in Honda vehicles. A malfunctioning PCV valve can exhibit a plethora of symptoms, from rough idling to increased oil consumption. Recognizing these signs early can save both time and money, ensuring that your engine maintains peak performance and efficiency. In this guide, we’ll delve into the intricacies of the PCV valve and its critical role in your Honda’s engine health.

Honda Accord PCV Valve Symptoms And Solutions

  • Your Check Engine Light Will Display On Your Dashboard
  • Rough Idle And High Idle RPM
  • Rich/Lean Mixture
  • Misfiring
  • Rough Acceleration
  • Oil Leaks And Increased Oil Consumption
  • Black, Blue, And White Smoke From Your Vehicle’s Exhaust
  • Contaminated Filter
  • Unusual Engine Noises

Your Check Engine Light Will Display On Your Dashboard

The illumination of the check engine light on your dashboard is a clear indication of potential issues with your car. While it can be triggered by many factors, a malfunctioning PCV valve is often a common culprit.

Solution: Use an OBD2 scanner to read the problem code from your engine control unit. If the code points towards the PCV system, consider replacing the valve or consulting a mechanic for further assessment.

Rough Idle And High Idle RPM

When your PCV valve isn’t functioning correctly, it can disrupt airflow in the intake manifold and crankcase. This disruption often manifests as high idle RPM or an irregular and rough idle.

Solution: Inspect the PCV valve for damage or clogs. Clean or replace it if necessary. Additionally, ensure there’s no leakage in the hoses connected to the PCV system.

Rich/Lean Mixture

A faulty PCV valve can create an imbalance in your air/fuel mixture. When rich, you may notice a gray/white exhaust and a distinct petrol odor. A lean mix, on the other hand, often results in misfires.

Solution: Regularly check the PCV valve for clogs or malfunctions. Cleaning or replacing the valve can often rectify the mixture imbalance. If the problem persists, consult a mechanic to diagnose any underlying issues.


Misfires can occur during acceleration and idle due to an incorrect fuel mixture. This is frequently attributed to a malfunctioning PCV valve.

Solution: Replace the PCV valve. If misfiring continues, inspect other parts of the ignition system, such as spark plugs and coils, for potential issues.

Rough Acceleration

Incorrect fuel mixtures, often resulting from a failing PCV valve, can cause rough acceleration both at low and high RPMs.

Solution: Inspect and clean or replace the PCV valve. Ensure that the entire PCV system, including hoses and connections, is intact and free of leaks.

Oil Leaks And Increased Oil Consumption

If the PCV valve or hoses get blocked, the pressure in the engine crankcase can increase, causing oil to leak.

Solution: Regularly inspect your PCV valve and related hoses for clogs. Cleaning or replacing the components can alleviate oil leaks and prevent excessive oil consumption.

Black, Blue, And White Smoke From Your Vehicle’s Exhaust

A compromised PCV system can force oil into combustion chambers, leading to blue exhaust smoke. Incorrect mixtures can produce black or white smoke.

Solution: Clean or replace the clogged PCV valve and inspect the hoses and connections. If smoke persists, it’s essential to consult with a mechanic to diagnose and rectify the issue.

Contaminated Filter

A malfunctioning PCV valve can lead to clogging in the breather element, affecting fuel efficiency.

Solution: Replace the PCV valve and clean or replace the breather element. Regularly monitoring the filter for signs of buildup can prevent future complications.

Unusual Engine Noises

Broken PCV valves or hoses can lead to odd engine noises, such as a whining or whirring sound.

Solution: Check the PCV valve and hoses for signs of damage or wear. Replace them if necessary. If the noises persist, it may be wise to have your engine inspected by a professional for any underlying issues.

How Do You Know If The PCV Valve Is Bad?

The PCV (Positive Crankcase Ventilation) valve is a critical component in most internal combustion engines. If it’s malfunctioning, you might observe several signs. The most common indication is the illumination of the check engine light on your dashboard. 

Additionally, a bad PCV valve can lead to rough idling, oil leaks, increased oil consumption, and an imbalance in your air/fuel mixture. In some instances, you might also notice unusual engine noises, such as a whining or whirring sound, indicating that the valve or its hoses might be damaged.

What Happens When A PCV Valve Goes Bad?

When the PCV valve goes bad, it can disrupt the engine’s ability to vent the crankcase. This malfunction can lead to increased pressure within the engine, potentially pushing oil up and out, leading to leaks and increased oil consumption.

A defective PCV valve can also affect the engine’s air/fuel mixture, causing it to run either too rich or too lean. Both scenarios are detrimental and can reduce engine efficiency, increase emissions, and even lead to engine damage over time.

What Are The Symptoms Of A Bad PCV Valve In A Honda?

For Honda vehicles, a bad PCV valve can manifest several symptoms, many of which are similar to other car makes. Honda owners might notice a check engine light illuminating, accompanied by rough idling or high idle RPM. 

Additionally, there might be issues related to a rich or lean air/fuel mixture, evident from gray/white exhaust smoke or a distinct petrol odor. Misfires during both acceleration and idle are common symptoms too. 

Additionally, you may witness rough acceleration, increased oil consumption, and oil leaks. Another Honda-specific symptom might be unusual engine noises, which can indicate a broken PCV valve or hose.

How Do You Test A Honda PCV Valve?

Testing a PCV valve in a Honda, or any other vehicle, is relatively straightforward. First, locate the PCV valve, typically found on the valve cover. Remove it from the valve cover and shake it. If you hear a rattle, it’s likely still functional. If it doesn’t rattle, it might be clogged and needs replacement. Another method involves running the engine and putting your finger over the end of the PCV valve. 

If it’s working correctly, you should feel a strong vacuum pull. If there’s no suction or if it’s weak, the valve might be faulty or there could be a blockage in the system. Always consult the vehicle’s manual for specific procedures and consider seeking a mechanic’s expertise for accurate diagnosis.


How often should I check my Honda Accord PCV valve?

Typically, every 20,000 to 50,000 miles. However, refer to your Honda Accord manual for specific intervals.

What’s the cost of a honda accord PCV valve symptoms replacement?

Depending on the model and where you get the service, the replacement usually ranges from $50 to $200.

Can I drive with a malfunctioning PCV valve?

It’s not advisable. Failing to address honda accord PCV valve symptoms might lead to more severe engine problems in the future.


Your Honda Accord’s PCV valve plays an essential role in ensuring smooth engine performance. Recognizing the Honda accord PCV valve symptoms and timely Honda accord PCV valve symptoms replacement will not only enhance your car’s efficiency but also prevent potential engine damage. Always consult a professional if you’re unsure about the health of your PCV system.

Also Read: Honda Accord Electric Parking Brake System Problem

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Ammar Masoud

I have had a long and fulfilling career in the automotive industry, primarily with Honda and Acura. With 15 years of experience as a Honda service technician, I became highly skilled in repair and maintenance, gaining a deep understanding of these vehicles. After many years in the automotive field, I decided to embark on a second career in industrial manufacturing. It was a significant change, but I found that the skills I had honed in the automotive industry were incredibly valuable in my new role. In my current position in industrial manufacturing, the demand for quality workmanship and meticulous attention to detail is paramount. Fortunately, these are traits that I have cultivated throughout my years in the automotive industry. I take pride in applying these skills to meet the high standards expected in the manufacturing sector.