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

If your M50, M52, or M54 engine takes a few seconds to build oil pressure after sitting, there's a good chance that your factory oil filter housing drain back valve has failed. Over time, the factory plastic check valve degrades, allowing oil to drain completely out of the housing and back into the oil pan while sitting. Every cold start essentially becomes a dry start, resulting in a loud ticking noise and causing unnecessary wear on your engine's internals.

Unfortunately, BMW does not offer this check valve as a standalone part, forcing you to purchase a costly, complete oil filter housing assembly just to fix one failed plastic component. Thankfully, our team of BMW enthusiasts took note of this common failure mode and designed a permanent, cost-effective fix.

Our Billet Oil Filter Housing Drain-Back Valve is designed as a direct-fit upgrade for your factory oil filter housing. CNC-machined from high-strength billet aluminum, this upgraded valve restores positive sealing to keep the oil filter housing fully primed. Maintaining this hydraulic prime ensures rapid oil pressure stabilization upon startup, directly mitigating dry-start bearing wear and top-end lifter starvation without requiring the purchase of a complete OEM housing assembly.

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.

*Click here for catch can instructions*

Features:

• 6061-T6 billet machined body, anodized black for lasting protection and appearance
• Strategically positioned 4 chamber baffle system maximizes oil / air separation 
• Knurled and black anodized oil dipstick makes inspecting oil volume of reservoir clean and simple
• Sealed with a pre-installed viton o-Ring
• Includes 2.5mm allen key to remove baffle plates for cleaning
• Engineered to create multiple changes in the direction of airflow within the separator to cause oil droplets to fall out of suspension before exiting the catch can
• Closed / recirculated design reduces oil ingestion and promotes cleaner emissions and odor-less operation
• Valved drainage system - no removal of can necessary to empty