Valve Cover Diaphragm – BMW B58 | OEM 11127645173

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

• BMW

Returns and exchanges

Request a change-of-mind return within 14 calendar days of delivery, then send the goods within 14 calendar days of notifying us. Our voluntary return option applies to unused, uninstalled, complete goods in their original condition and packaging. Exchanges are subject to availability and agreement.

The customer pays change-of-mind return shipping. No restocking fee applies. Refunds and original delivery charges are handled under our Refund & Return Policy and applicable law.

Faulty, damaged or incorrect goods

Email contact-us@klifex.net with your order details and a description of the problem. These claims are separate from change-of-mind returns. Where we are responsible, we bear the required remedy and return costs. Installation alone does not remove mandatory defect rights.

Your legal rights

Applicable statutory rights take precedence, including EU/EEA and UK withdrawal rights and legal guarantees. Necessary inspection does not remove a statutory withdrawal right; deductions for excessive handling must reflect an actual, evidenced loss of value.

Contact us for the correct return address before shipping. Our legal address is not a return address.

Read the full Refund & Return Policy