Oil Separator Repair Kit with 52mm Diaphragm - Mercedes M278 V8 4.0L / 4.6L and M157 5.5L / 6.0L - 2780100431

This oil separator repair kit includes a 52 mm ventilation diaphragm for the listed Mercedes M278 V8 4.0L/4.6L and M157 5.5L/6.0L applications. A worn membrane can disturb crankcase pressure, admit unwanted air and contribute to oil consumption or unstable idle.

Applications

• Mercedes Benz ML-class / GLE (w166)
• Mercedes Benz GL-class / GLS (x166)
• Mercedes Benz SLK/SLC (r172)
• Mercedes Benz E-class (c207, a207)
• Mercedes Benz E-class (w212, v212)
• Mercedes Benz E-class (s212)
• Mercedes Benz CL-class (c216)
• Mercedes Benz CLS-class (c218, x218)
• Mercedes Benz S-class (w221, v221)
• Mercedes Benz SL-Class (r231)
• Mercedes Benz G-class (w463)
• Mercedes Benz S-class Coupe (c217)
• Mercedes Benz S-class (w222, v222, x222)
• Mercedes Benz GLE Coupe (c292)
• Mercedes-Benz C-Class / R-Class.

Ventilation Symptoms to Investigate

• Whistling or excessive crankcase vacuum.
• Unstable engine idle.
• Increased engine oil consumption.
• Oil deposits in the intake.
• Exhaust smoke after warm-up.
• Mixture faults associated with unwanted air.

Inspect the ventilation system and confirm the faulty component; symptoms alone do not prove that the membrane or valve is the cause.

Diameter, Engines and References

Diaphragm diameter: 52 mm. Engine designations: M278 V8 4.0L, 4.6L; M157 5.5L, 6.0L. Compare reference forms 2780100431 and A2780100431 and the original diaphragm seating.

Repair Scope

Repairing a worn diaphragm or ventilation element can restore crankcase ventilation and reduce unwanted air entry. A separate repair is suitable only when the housing remains serviceable. Inspect the cover or separator body and ventilation hoses for cracks; a damaged housing may require replacement of the assembly. Increased oil consumption may have other engine causes.

Important Before Ordering

Compare the original part number, marking, shape and mounting design before ordering. A model name alone does not confirm the required version.

FAQ

What is the diaphragm diameter?

52 mm.

Can the separator be repaired separately?

A separate repair is suitable if the housing is intact and the ventilation element is the cause of the fault.

Part Number / PN

2780100431,A2780100431

SKU: KLA2780100431.

• Mercedes

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