11127645173 Valve Cover Diaphragm for BMW B58
This valve cover diaphragm is designed for BMW B58 engines using OEM reference 11127645173. It replaces the failed PCV membrane in the valve cover crankcase ventilation system and helps restore correct pressure regulation.
This product is the diaphragm only. It is not a complete valve cover assembly or full PCV repair kit.
OEM / Reference Numbers
Primary OEM / valve cover reference number:
- 11127645173
Secondary OEM / reference numbers:
- 11121025447
- 11 12 7 645 173
Product reference:
- SKU: KL11127645173
Part Type
- valve cover diaphragm
- PCV membrane
- crankcase ventilation diaphragm
- engine breather membrane
- oil separator diaphragm
What This Part Does
The valve cover diaphragm regulates crankcase pressure and controls blow-by gas flow through the PCV system. When the original membrane tears or hardens, the system can lose correct pressure control and cause ventilation-related running issues.
Replacing the failed diaphragm helps restore PCV function while keeping the existing BMW B58 valve cover in service.
Compatible Vehicles
This valve cover diaphragm is listed for BMW B58 engine applications.
- BMW B58 applications using compatible valve cover reference 11127645173
- BMW M140i
- BMW M240i
- BMW 340i
- BMW 440i
- BMW 540i
- BMW 740i
- BMW X3 M40i
- BMW X4 M40i
Engine / Engine Family
- BMW B58
- BMW turbocharged petrol engine application
Common Symptoms of Failure
- rough or unstable idle
- whistling or suction noise from the valve cover area
- vacuum leak symptoms
- increased oil consumption
- incorrect crankcase pressure
- oil vapor issues in the intake system
Why Choose This Replacement
- Targets the exact repair intent for 11127645173
- Standalone PCV membrane for BMW B58 valve cover repair
- Supports related reference 11121025447
- Cost-effective alternative to replacing the complete valve cover when only the diaphragm has failed
- Helps restore crankcase ventilation and pressure control
Important Before Ordering
- Check that your original valve cover reference matches 11127645173 or a listed related reference.
- Confirm that your vehicle uses a BMW B58 engine.
- Compare the 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 does BMW 11127645173 fit?
BMW 11127645173 is listed for valve cover diaphragm repair on BMW B58 engine applications using compatible valve cover designs.
Is 11121025447 related to 11127645173?
Yes. 11121025447 is listed as a related reference for this BMW B58 valve cover diaphragm application. The main focus remains OEM 11127645173.
What does this BMW B58 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 BMW B58 engines?
Common symptoms include rough idle, whistling noise, vacuum leak symptoms, increased oil consumption, incorrect crankcase pressure and oil vapor issues.
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 number 11127645173 or a listed related reference, check that your vehicle uses a BMW B58 engine, and compare the diaphragm with your original 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