BMW Z Series E85/6 (2003-2008)

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.

If allowed in the rules these solid aluminum engine and transmission mounts offer many advantages over a urethane or Delrin mounts. It's no wonder that these mounts have found their way into the top BMW racers in the country. These are machined from solid aluminum and have zero deflection, engine torque will cause a rubber or urethane mount to flex or deflect allowing more torque to passed through the drive line (instead of being wasted winding up the mount). When paired with our flex-free solid transmission mounts you'll get smoother, crisper shifts since the transmission is no longer dancing on the pliable mount. This puts the shift linkages in better consistent alignment. And unlike rubber or urethane the aluminum has zero wear and is not affected by leaking oil or other fluids so this is likely the last set of motor and transmission mounts you will ever need. We very strongly recommend using the solid transmission and engine mounts together as a complete kit, mixing a rubber mount with a metal mount will cause undue stress on the mounting points and will lead to a failure. We never advise using a solid engine mount unless a corresponding solid transmission mount is also used.

These are a no-compromise design for all-out racing use, full solid aluminum mounts should not be used on street-driven cars since there is no material to absorb vibration making these quite harsh for regular street use (track cars don't care about noise).

Product features and benefits:

• Crisper throttle response, positive shifter location, direct power transfer
• Precision machined billet 6061-T6 aluminum housing
• Black anodized for durability and corrosion resistance
• Grade 10.9 stud - fear not, big turbo owners
• Engineered in-house and made in America

This item fits the following BMWs:
2008-2013 E82 E88 BMW 128i 135i 1M Coupe
2006-2011 E90 BMW 325i 325xi 328i 328xi 330i 330xi 335d 335i 335xi - Sedan
2007-2011 E91 BMW 325i 325xi 328i 328xi - Touring Wagon
2007-2013 E92 BMW 328i 328xi 335i 335is 335xi - Coupe
2007-2013 E93 BMW 328i 335i 335is - Convertible
2009-2016 E89 BMW Z4 sDrive30i Z4 sDrive35i Z4 sDrive35is

Over time, the factory valve cover hardware on M50, M50TU, M52, M52TU, M54, S50 (US), and S52 engines is subjected to continuous heat cycling, oil vapor, and moisture, causing original cap nuts to oxidize, corrode, or thread-strip during routine maintenance. Our Polished Valve Cover Cap Nut serves as a direct replacement designed to address these common failure points while improving upon overall engine bay aesthetics.

Because maintaining precise gasket compression is critical to preventing oil leaks, these cap nuts and washers are machined directly to OE-style dimensions. This exact fitment allows for direct compatibility with original and replacement valve cover studs (see T#55317643) and ensures the hardware can be torqued precisely to OEM specifications without guesswork. Manufactured to grade 8.8 structural strength standards, the hardware maintains the necessary clamp force required under normal and high-performance engine operating conditions.

To resist corrosion, both the cap nut and washer undergo an electroless nickel plating process during production. Unlike standard zinc coatings that dull or rust over time, electroless nickel provides a uniform layer of corrosion resistance that withstands long-term chemical exposure and extreme temperature swings while giving the hardware a polished, high-end appearance. Each cap nut assembly includes an OE rubber washer seal, ensuring a tight, leak-free barrier that prevents oil from escaping through the mounting studs.