Emissions System for BMW 3 Series E46 (1999-2005)

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. 

Modern emission regulations require a closed PCV/Breather system for cleaner operation. However, inefficient oil particle capture can lead to excessive oil vapor ingestion, causing carbon buildup, reduced performance, and fuel economy. ECS Tuning's updated ECS Baffled Oil Catch Can, now with an easy-to-empty 1/4" drain fitting, is engineered to collect toxic blow-by gases, minimize carbon deposits, and reduce oil contamination within engine oil. Recirculating oil vapor ensures emissions compliance without venting to the atmosphere.

• Key Features:
• Highly Efficient Oil Separator: Strategically positioned 4 chamber baffle system maximizes oil/air separation and minimizes oil droplets in the intake tract.
• Integrated Dipstick: Knurled and black anodized oil dipstick simplifies oil volume inspection.
• Reservoir: Available in 6oz or 8oz capacity with a 1/4" NPT drain plug fitting.
• Serviceable: Easily removable baffle plates and drain plug for cleaning.
• Easy/Customizable Installation: Combine with the ECS Universal Bracket Kit for simplified installation and adjustable mounting locations.
• Leak-Free Fittings: Machined -10AN ORB (O-Ring Boss) fittings available for secure connections (fittings sold separately).

Modern day emissions regulations require the use of a closed crankcase ventilation (PCV) system to recirculate combustion blow-by gases from the crankcase back in to the intake to be burned.  Unfortunately, these blow by gases contain water vapor (which is a byproduct of combustion) and pick up oil mist from and the windage cloud and cam lubrication system as they travel through the crank case.  Due to less than 100% effective air/oil separation in the stock PCV system, some oil mist and water vapor gets carried back to the intake tract and over time cause oil deposits in the intake manifold, intake ports, and on the back of intake valves.  All will eventually lead to poor performance and reduced fuel economy, and the presence of this oil mist in the intake charge may even increase the risk of engine-damaging detonation. 

With forced induction, track use, and/or extended high RPM usage, these symptoms increase as the factory PCV system is overwhelmed, and a catch can becomes a must for your E46 M3. This kit is a direct fit making this an easy reversal if desired as well as maintaining a clean appearance by utilizing the open "smuggler's compartment" on the passenger side of the engine bay.

ECS engineers developed a catch can that utilizes a strategically designed 4 chamber baffle plate system engineered to create multiple changes in the direction of airflow to cause oil droplets to fall out of suspension, maximizing the efficiency of the PCV air/oil separation.  A dipstick is integrated into the cap so you can monitor the oil level, and the can is easily serviced.  At each oil change simply unscrew the canister and empty the trapped oil with your regular used oil.  The ECS Oil Catch Can is CNC machined from billet 6061-T6 aluminum and with a stealthy black anodized finish for lasting durability and appearance, and includes everything needed for an OEM-like fully reversible installation.  

The ECS Oil Catch Can is made from aluminum and with a stealthy black anodized finish. The location is key as heat will evaporate the oil and send too much vapor back into the engine (where cooler air will turn it back into fluid). The ECS OCC also has a factory-like appearance. Having a kit designed specifically for your E46 M3 makes for a clean looking setup that any skill level mechanic can install. 

Note: Since the crankcase vent system is considered part of the overall emissions system, installing this may be a violation of local, state, and federal laws. While exemptions are made for track/race and off-road use, check with your local state inspection facility on using this in street-driven vehicles.

*Click here for installation instructions*

ECS Oil Catch Can Features:
+ Increases air intake efficiency
+ Promotes engine longevity
+ 4 chamber design promotes excellent air/oil separation
+ Large In/Out ports (no tapered sizes that slow flow)
+ Anodized black lightweight aluminum
+ Made in USA

This item fits the following BMWs
E46 M3 2001-2006

Upgrade your exhaust system with the Stainless Steel Oxygen Sensor (O2) Weld Bung (M18x1.5mm). This high-quality weld bung is made from stainless steel, ensuring durability and resistance to corrosion. It features M18x1.5mm threads, making it compatible with most oxygen sensors. Perfect for custom exhaust setups or replacing damaged bungs, this weld bung is a must-have for any automotive enthusiast.

• Made from high-quality stainless steel for durability and corrosion resistance
• M18x1.5mm threads ensure compatibility with most oxygen sensors
• Ideal for custom exhaust setups or replacing damaged bungs
• Essential for automotive enthusiasts looking to upgrade their exhaust system

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:
09/2004-2006 E46 BMW M3 - Manual Transmission