Information
Non-Return Valve – Crankcase Oil Breather
The crankcase oil breather non-return valves is an
essential part of your Porsche’s engine ventilation system. Designed to OEM
specifications, they regulate crankcase pressure, prevent oil vapour backflow,
and ensure smooth, efficient engine operation. Replacing both valves together
restores proper crankcase breathing and protects your engine from leaks and
excess oil consumption.
Fits:
- Porsche Cayenne V6 3.6L Petrol 300Hp
- Porsche Panamera S V6 Turbo 3.0L 2WD
(420Hp)
- Porsche Panamera S V6 Turbo 3.0L 2WD
Executive
- Porsche Panamera 4S V6 Turbo 3.0L 4WD
(420Hp)
- Porsche Panamera 4S V6 Turbo 3.0L 4WD
Executive
- Porsche Macan S Petrol 3.0L V6 340Bhp
- Porsche Macan GTS Petrol 3.0L V6 360Bhp
- Porsche Macan Turbo 3.6L V6 400Bhp
Diagram Ref No 1 and 2
What the Non Return Valves Do
- Maintain Correct Pressure: Allow gases to escape while preventing
backflow into the crankcase.
- Improve Engine Efficiency: Reduce oil vapour re-entry, helping
cleaner combustion.
- Protect Components: Prevent pressure build-up that can damage seals
and gaskets.
Symptoms of Faulty Breather Valves
- Excessive oil consumption.
- Blue smoke from the exhaust.
- Oil leaks around gaskets and seals.
- Rough idle, misfires, or poor performance.
- Strong smell of oil fumes in the engine bay or cabin.
Common Reasons for Failure
- Oil Sludge & Contamination: Causes the valve to stick open or
closed.
- Rubber & Spring Wear: Degradation over time reduces
effectiveness.
- Lack of Maintenance: Old oil accelerates valve failure.
- High Mileage Stress: Heat cycles and pressure changes weaken
components.
Why Replace?
Restores proper crankcase ventilation.
Prevents oil leaks and excess pressure in the engine.
Reduces harmful emissions and oil consumption.
Protects seals, gaskets, and other critical engine parts.
Improves reliability, performance, and long-term durability.
Why Buy from Design 911?
- Specialist Supplier: We are Porsche parts experts with years of
experience.
- OEM Quality & Fitment: Parts meet or exceed original
specifications.
- Trusted Worldwide: Thousands of Porsche owners and workshops rely
on us.
- Comprehensive Support: Expert advice, fast shipping, and
hassle-free service.
- One-Stop Shop: Whether it’s engine, body, or interior components,
Design 911 has you covered.
Ideal For: Replacing worn crankcase valves during
servicing or resolving oil consumption, leaks, or performance issues.
Related reference numbersRelated, superseded, cross reference or alternative numbers for comparison.
9461072The product you are viewing cross references to these numbers