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

Rally Road Productions, Inc. is a team supported by a group of people with great abilities in their area of expertise. From the "web guy" and driving instructor friends, to owners of various machine shops, they have surrounded ourselves with people that can be trusted to create and manufacture quality products. This is the key to ensuring everything that they sell will perform as it was intended. The goal is to increase customer satisfaction and make the customization or performance enhancement of your vehicle a more enjoyable venture.

This oil cooler system is race tested and proven to outflow the euro M3 oil filter housing. Additionally, this particular system uses a sealing mechanism to direct the oil flow through the cooler lines and then through the oil filter.  Other cooler caps do not provide this seal and therefore the external oil coolers and lines act as a "balloon".  The lines and cooler are pressurized, but oil does not flow through them.  Flowing oil means it is being cooled and not just acting as an external reservoir.

Flow testing reveals that the oil cooler cap will outflow the Euro M3 Oil Filter Housing by more than 80% at the same, pressure, RPM, and oil temperature. In the upper RPM range, there is nearly a 100% improvement in flow from the RallyRoad oil cooler cap when compared to the Euro M3 oil filter housing.  This is a massive improvement over OE and is a worthwhile upgrade, especially in engines that see severe duty.

Features:

• -8AN o-ring ports to provide a leak free fitting without the use of Teflon tape or sealant used by other oil cooler caps.
• Viton o-rings are used throughout to maintain function and sealing in a high-temperature oil environment.
• Use of the stock filter cap bolt to reduce cost and simplify installation.
• An internal sealing mechanism to direct oil flow through the oil cooler and through the filter.
• 1/8" NPT side port for external oil pressure gauge.

Kit Includes:

• Oil filter cap with fittings
• Oil filter sealing ring
• BMW MANN Oil Filter and gasket

This part fits the following BMWs
1992-1999 E36 323i 325i 325is 328i 328is