Oil Separation & Breather System

When your CPV O-ring fails it causes a slow oil leak on the passenger side of the engine, making an oily mess that frequently resembles a rear main seal leak. Replacing the CPV with an upgraded o-ring ensures a long-term solution to this common problem. 

The factory o-ring over time fails from heat cycling and oil exposure due to the Buna rubber used in OEM o-rings, while the included Viton Fluoroelastomer is resistant to a much higher temperature to ensure prolonged life without leaking. 

Elevate your S63 4.4L engine's capabilities with our meticulously designed Crank Case Vent Hose Kit. Crafted from premium-grade materials, this kit ensures superior ventilation, mitigating pressure accumulation within the engine, thereby enhancing its overall performance.

Engineered to precise specifications, our kit seamlessly replaces the OEM vent hoses, guaranteeing a perfect fit. By reducing stress on the engine, it prolongs its lifespan and maintains peak functionality. Rely on this kit to provide unparalleled performance and unwavering reliability for your S63 4.4L engine.

Connecting the cyclone oil separator to the engine valve cover, this hose is crucial for maintaining optimal engine performance. Over time, exposure to heat from engine components can cause the plastic hose to become brittle, resulting in cracks, tears, or splits. These issues can lead to vacuum and oil leaks, triggering a check engine light.

• High-quality replacement for BMW crankcase vent hose
• Ensures optimal engine performance
• Resistant to heat and wear
• Helps prevent vacuum and oil leaks
• Easy to install

For your BMW's optimal performance, ensure the functionality of the hose connecting the oil dipstick to the crankcase vent valve. Positioned below the intake manifold, this hose is susceptible to clogging with oil film and condensation, leading to potential failure over time. Cracks and swelling in old hoses can result in oil and vacuum leaks, compromising engine performance.

• Essential component for BMW engine functionality
• Prevents clogging and potential hose failure
• Minimizes oil and vacuum leaks
• Convenient replacement when replacing crankcase vent valve

Includes connector housing with terminals and seals. Commonly used for the idle air control valve (IACV).

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 12521706096 - Commonly used for the idle air control valve (IACV).

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

This tube runs from the oil separator to the lower dipstick tube.

BMW has an ongoing issue with oil separators freezing in cold weather if driving is done before the vehicle is fully warmed up. There is often a howling noise followed by numerous oil leaks. The crankcase breather valve is used to purge the oil vapor from the engine block into the valve cover. However, sometimes condensation can cause it to freeze, causing the entire oil separator system to fail, crack, and disintegrate.

Replace this and all the other components of the oil separator system to prevent damage to all the aspects of your engine. As long as you have everything off, you can rest assured that new parts will last and be reliable.

The hoses and oil separator can crack or become faulty, leading to vacuum leaks or oil leaks. This is caused by the stress the plastic components are exposed to during heating and cooling cycles, especially if the vehicle is not brought up to operating temperature during driving in cold weather climates.

This kit includes the needed hoses, oil separator, and hardware.

Fits the following BMWs:
2001-09/2004 E46 BMW M3 - Manual Transmission