* PCV System Purpose: The PCV system is designed to vent harmful crankcase pressure and blow-by gasses back into the intake manifold to be burned in the combustion chamber.
* Oil Separation: The PCV valve itself is designed to filter out oil from the crankcase gasses. If the PCV system is working correctly, it should capture most of the oil before it reaches the intake manifold.
* High Speed Considerations: While high engine speeds can increase crankcase pressure, a properly functioning PCV valve should be able to handle this.
However, there are a few scenarios where you might see oil being blown out, even with a PCV system in place:
* Faulty PCV Valve: A damaged or clogged PCV valve can restrict airflow, leading to excessive crankcase pressure. This pressure might force oil past seals or even blow oil out of the crankcase breather hose.
* Oil Separator Issues: Some PCV systems have an oil separator that helps remove oil from the gasses. A faulty separator can allow more oil to pass through.
* Engine Problems: Other engine issues like worn piston rings, damaged valve seals, or a failing head gasket can lead to excessive oil blow-by, which might overwhelm the PCV system.
If you're experiencing oil being blown out at high speed, it's important to address the issue:
1. Inspect the PCV Valve: Ensure the valve is functioning correctly and is not clogged. Replace if necessary.
2. Check for Leaks: Inspect the PCV system hoses and connections for leaks.
3. Consider Engine Condition: If the oil blow-by seems excessive, consider a more thorough engine inspection to rule out any underlying engine problems.
Note: It's always best to consult a qualified mechanic to diagnose and address any engine issues, including oil blow-by.
