Know the Function of the PCV System in Car Engines and How It Works
The function of the PCV (Positive Crankcase Ventilation) system in the engine is to expel blow-by gas through the combustion process and redirect it back to the cylinder for re-combustion. Blow-by gas itself is gas that fails to combust, thus still containing high levels of hydrocarbons. In addition to the above function, the PCV system has other equally important functions for the performance of the car engine. For more details, please refer to the following review.
Function of the PCV (Positive Crankcase Ventilation) System in Car Engines
The PCV (Positive Crankcase Ventilation) system is a system found in car engines. This system has several important functions as follows.
1. Preventing air pollution
As is known, when a car combusts in the combustion chamber, it produces emission gases or exhaust gases. These gas emissions will later be expelled through the exhaust valve, but not entirely. Some residual gas emissions can sneak into the engine block space. This gas is often referred to as blow-by gas.
To prevent blow-by gas from creating excessive pressure, the gas will be expelled into the air. However, this process of expelling blow-by gas into the air causes high air pollution. This is because blow-by gas has high levels of unburned hydrocarbons. Additionally, blow-by gas also contains oil vapor that contains toxic and harmful substances if inhaled by humans.
With the presence of this PCV system, blow-by gas will be redirected back to the intake of the combustion chamber. This way, blow-by gas can be burned again, thus reducing air pollution.
2. Preventing oil sludge
Oil sludge or oil coagulation in the engine cavity can occur due to engine oxidation or failure of blow-by gas combustion. The PCV system itself allows blow-by gas to be burned again during the combustion process.
3. Improving engine performance and fuel efficiency
The next function of the PCV system is to improve engine performance and make engine consumption more efficient. This can occur because the combustion process in the combustion chamber can work well.
How the PCV System Works in Car Engines
After knowing the function of the PCV system, you need to understand how it works. Here is the complete working mechanism.
1. When backfiring or the engine is off
When the car engine is in a backfiring condition or off, the PCV valve will close. This happens because the PCV plunger closes the airflow, causing the intake to be pressed and automatically closing the PCV. As a result, the engine space does not receive any air at all.
2. When the engine is in deceleration or idle
When the engine is in a deceleration or idle state, the PCV plunger opens. This condition occurs because the PCV plunger is pulled by the intake vacuum. Thus, blow-by gas can flow into the intake of the engine space.
3. When the engine is running normally
When the car is running normally, the PCV plunger will open. This condition allows more blow-by gas to be directed to the intake of the engine space.
4. During maneuvering
When the car is maneuvering or accelerating, the intake vacuum will increase. This happens because the blow-by gas also increases, allowing it to push and fully open the PCV plunger. This way, the flow of emission gases into the engine becomes greater.
Considering its important function in redirecting emission gases to the intake manifold, you should pay attention to the condition of your car's PCV system. Immediately visit the nearest Daihatsu workshop if the PCV valve is stuck or clogged to ensure the engine performance is always at its best.
