Valve Cover Breather vs PCV: Understanding the Key Differences

Valve cover breather and PCV (Positive Crankcase Ventilation) are two vital components of an internal combustion engine that are designed to regulate the engine’s air pressure and ventilation. These parts are often confused with one another, but they have distinct differences that make them unique.

In this article, we will discuss the differences between valve cover breather vs PCV, their key features, pros and cons, comparison table, and recommendations to help you decide which is best for your engine.

Valve Cover Breather

A valve cover breather is a simple device that allows air to escape from the engine’s crankcase. It works by venting the excess air that builds up inside the engine and releasing it into the atmosphere. The valve cover breather typically consists of a small filter that is attached to the valve cover.

Key Features

Here are some key features of valve cover breather –

Simple design: A valve cover breather is relatively simple and does not require any complex mechanisms.

Cost-effective: Valve cover breathers are affordable and easy to install, making them an ideal choice for budget-conscious drivers.

Increased airflow: A valve cover breather provides increased airflow to the engine, which can result in improved performance.


  • Simple and affordable.
  • Easy to install.
  • Can release excess air pressure and improve performance.


  • May not be suitable for all engines.
  • May increase emissions.

PCV (Positive Crankcase Ventilation)

A PCV is a more complex system that is designed to regulate the pressure and ventilation within the engine. It works by drawing air from the crankcase and recirculating it back into the engine’s intake manifold. The PCV system typically consists of a valve, hoses, and a canister.

Key Features

Here are some key features of PCV (Positive Crankcase Ventilation)

Efficient: A PCV system is designed to be efficient, providing optimal ventilation and reducing the risk of engine damage.

Reduces emissions: By recirculating air back into the engine, a PCV system can help to reduce emissions.

Designed for modern engines: PCV systems are designed for modern engines, making them an ideal choice for those who drive newer vehicles.


  • Complex and effective.
  • Can reduce emissions.
  • Provides optimal ventilation and improves performance.


  • Designed for modern engines.
  • Requires professional installation.
  • More expensive.

Valve Cover Breather vs PCV Comparison Table

FeatureValve Cover BreatherPCV
Suitable for allNoYes
Reduces EmissionsMay IncreaseReduces

Valve Cover Breather vs PCV: Which is Best?

If you have a newer engine, a PCV system may be the better option as it is specifically designed for modern engines and provides optimal ventilation. However, if you’re looking for a more cost-effective and simpler solution, a valve cover breather may be the better choice.

Ultimately, it’s important to consider the pros and cons of each option and determine which one will work best for your specific situation. It’s also recommended to consult with a mechanic or automotive professional for their expert opinion and advice.


After comparing valve cover breather vs PCV, we got both systems have their advantages and disadvantages when it comes to engine ventilation. While valve cover breathers are a simple and cost-effective option, they may not be suitable for all engines and may increase emissions. On the other hand, PCV systems are a more complex and effective option that can improve engine performance and reduce emissions but may be more expensive and require professional installation.

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