11128571308 / 11128511342 Valve Cover Diaphragm for BMW B57, B57S, B37
This valve cover diaphragm is designed for BMW B57, B57S and B37 engine applications using OEM references 11128571308 and 11128511342. It replaces the failed PCV membrane in the valve cover crankcase ventilation system.
This product is the diaphragm only. It is not a complete valve cover assembly or full crankcase ventilation valve.
OEM / Reference Numbers
Primary OEM / valve cover reference numbers:
- 11128571308
- 11128511342
Secondary OEM / reference numbers:
- 11128575408
Product reference:
- SKU: KL11128571308
Part Type
- valve cover diaphragm
- PCV membrane
- crankcase ventilation diaphragm
- engine breather membrane
- oil separator membrane
What This Part Does
The valve cover diaphragm regulates crankcase pressure and controls blow-by gas flow through the PCV system. When the diaphragm fails, pressure control can become unstable and ventilation-related symptoms may appear.
Replacing the failed diaphragm helps restore the function of the existing valve cover PCV system while avoiding replacement of the complete valve cover.
Compatible Vehicles
This valve cover diaphragm is listed for BMW and MINI applications using compatible B57, B57S and B37 engine configurations.
- BMW B57 diesel applications
- BMW B57S diesel applications
- BMW B37 diesel applications
- MINI B37 diesel applications
Engine / Engine Family / Technical Detail
- BMW B57
- BMW B57S
- BMW B37
- MINI B37
- Membrane diameter: 51 mm
Common Symptoms of Failure
- incorrect crankcase pressure
- rough or unstable idle
- increased oil consumption
- oil vapor issues in the intake system
- whistling or suction noise from the valve cover area
- vacuum leak symptoms
Why Choose This Replacement
- Targets exact repair intent for 11128571308 and 11128511342
- Supports related reference 11128575408
- Replaces the failed 51 mm valve cover PCV diaphragm
- Cost-effective alternative to replacing the complete valve cover when only the membrane has failed
- Helps restore crankcase ventilation and pressure control
Important Before Ordering
- Check that your original valve cover reference matches 11128571308, 11128511342 or a listed related number.
- Confirm that your vehicle uses a compatible B57, B57S or B37 engine.
- Compare the 51 mm diaphragm design with the membrane installed in your original valve cover.
- This product is a valve cover diaphragm only, not a complete valve cover assembly.
- Verify compatibility by OEM number, engine type and part design before ordering.
FAQ
What do BMW 11128571308 and 11128511342 fit?
BMW 11128571308 and 11128511342 are listed for valve cover diaphragm repair on compatible BMW B57, B57S and B37 applications. The product page also references MINI B37 applications.
Is 11128575408 related to 11128571308?
Yes. 11128575408 is listed as a related reference for this valve cover diaphragm application. The main repair focus remains 11128571308 and 11128511342.
What does this valve cover diaphragm do?
The diaphragm regulates crankcase pressure and controls blow-by gas flow through the valve cover PCV system.
What symptoms indicate PCV diaphragm failure on B57 or B37 engines?
Common symptoms include incorrect crankcase pressure, rough idle, increased oil consumption, oil vapor issues, whistling noise and vacuum leak symptoms.
Is this a complete valve cover assembly?
No. This product is the valve cover diaphragm / PCV membrane only. It is not a complete valve cover assembly.
How do I confirm compatibility before ordering?
Confirm OEM reference 11128571308 or 11128511342, check the engine family, and compare the 51 mm diaphragm with your original valve cover membrane.
Read All
Orders ship within 1–2 business days.
Standard delivery:
- USA: Some items ship from our US warehouse and arrive within 3 business days.
- USA-EU: 10–21 business days
- Worldwide: 14–30 business days
Shipping cost is shown at checkout.
Can I exchange or return an item?
Yes, you can exchange or return an item within 14 days of purchase. This right is guaranteed to you by the Law on the Protection of Consumer Rights
To use this feature, please make sure that:
- the product was not in use and has no traces of use: scratches, chips, abrasions, etc.
- the goods are fully completed and the integrity of the packaging is not violated
- retained all labels and factory markings