BMW Engine Parts

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.

If you own an M57-equipped BMW, you already know this twin-turbo diesel powerplant is an absolute torque monster. What you might also know is that all that low-end grunt and high-compression diesel vibration wreaks absolute havoc on your accessory drive system.

From the factory, both the E90 335d and E70 X5 35d utilize a rigid alternator pulley. With each cylinder's fire, the crankshaft experiences a violent micro-acceleration. Because the alternator has a heavy internal rotor spinning at high speeds, it wants to keep spinning at a constant rate. When the engine suddenly slows down (even minutely between firing cycles), the alternator fights the belt. This constant tug-of-war results in extreme stress on your engine's belt-driven components. At best, it’s an annoying, unrefined chirp at idle; at worst, it’s a ticking time bomb for your expensive harmonic balancer.

To solve this issue, many enthusiasts choose to run a clutched alternator pulley (also called an overrunning alternator pulley). A clutched pulley allows the alternator to "freewheel" or coast when the engine slows down, completely isolating its rotational inertia from the belt drive to prevent component wear. While the N52's clutched pulley (12317560483) is a straight bolt-on, the offset is incorrect for the E70 35d's accessory drive. Thankfully, our engineers designed this zinc-coated spacer to provide the precise amount of spacing needed to perfectly align the new pulley with existing belt drive components.

If you own an M57-equipped BMW, you already know this twin-turbo diesel powerplant is an absolute torque monster. What you might also know is that all that low-end grunt and high-compression diesel vibration wreaks absolute havoc on your accessory drive system.

From the factory, both the E90 335d and E70 X5 35d utilize a rigid alternator pulley. With each cylinder's fire, the crankshaft experiences a violent micro-acceleration. Because the alternator has a heavy internal rotor spinning at high speeds, it wants to keep spinning at a constant rate. When the engine suddenly slows down (even minutely between firing cycles), the alternator fights the belt. This constant tug-of-war results in extreme stress on your engine's belt-driven components. At best, it’s an annoying, unrefined chirp at idle; at worst, it’s a ticking time bomb for your expensive harmonic balancer.

To solve this issue, many enthusiasts choose to run a clutched alternator pulley (also called an overrunning alternator pulley). A clutched pulley allows the alternator to "freewheel" or coast when the engine slows down, completely isolating its rotational inertia from the belt drive to prevent component wear. While the N52's clutched pulley (12317560483) is a straight bolt-on, the offset is incorrect for the E70 X5 35d's accessory drive. Thankfully, our engineers designed this zinc-coated spacer to provide the precise amount of spacing needed to perfectly align the new pulley with existing belt drive components.

Take the guesswork out of S54 ownership. This all-inclusive kit targets the two most notorious failure points on the BMW S54 engine: broken exhaust hub tabs and degraded internal seals.

Turner Motorsport S54 VANOS Exhaust Hub Upgrade

The factory S54 exhaust hub is a ticking time bomb. Excessive play between the drive tabs and the oil pump disk creates a rhythmic rattling that eventually shears the tabs off, risking catastrophic engine failure.

While other kits require deep-engine surgery, our Turner Motorsport Hub Upgrade offers a "work smarter" approach.

Precision Engineering: Developed using 3D scanning and CAD modeling for a perfect, interference-free fit.

Superior Materials: Machined from high-strength 4340 steel and hardened to OEM specifications.

No Re-Timing Required: This bolt-on fix eliminates the failure point without the need to disassemble the VANOS unit or disturb engine timing, saving hours of labor.

ECS Tuning VANOS Seal Kit

The original BMW seals are made of Buna-N rubber, which quickly hardens and loses its sealing properties when exposed to synthetic oil and high heat. Our ECS engineering team has corrected this flaw.

Viton™ Upgrade: We utilize high-performance Viton O-rings for the internal seals, seal plate, and solenoid.

Chemical Resistance: These seals are designed to remain pliable and effective for the life of the engine, restoring lost low-end torque and smoothness.

ECS Tuning Rattle Repair Kit

Eliminate the dreaded "marbles in a can" sound. This kit addresses the axial play in the VANOS helical gears.

Hardened Steel: Our rings and washers are precision-ground to resist the wear and deformation that lead to engine rattle.

Silent Operation: Restores the refined sound and feel of your S54 across the entire RPM range.

The factory VANOS exhaust hub on the S54 engine is known to develop excessive play where the drive tabs interface with the oil pump disk. Over time, this imprecise fitment causes a back-and-forth rattling motion that can result in the tabs shearing off inside the engine, risking catastrophic damage or complete engine failure. Unlike other aftermarket solutions that require full VANOS disassembly, retiming, or replacement of the oil pump disk, the Turner Motorsport S54 VANOS Hub Upgrade offers a smarter approach. Our bolt-on fix eliminates the common failure point without opening the VANOS unit or disturbing engine timing.

Our solution involves removing the worn tabs from your stock exhaust hub and installing our precision-fit replacement, which is precision-machined from 4340 steel and hardened to meet OEM specifications. Designed using 3D scanning and CAD modeling, the Turner Motorsport VANOS Exhaust Hub Upgrade provides a tight, interference-free fit into the oil pump disc, completely resolving the issue without unnecessary labor.

Features & Benefits:

Direct bolt-on solution for S54 VANOS oil pump drive tab failure, preventing potentially catastrophic damage to engine internals Precision-machined from high-strength 4340 steel and heat-treated to match OEM specifications Designed using 3D scanning and CAD modeling to ensure precise fitment within the OEM oil pump disc Engineered to eliminate the play that exists between the exhaust hub and oil pump disc from factory Backed by extensive real-world testing and our lifetime replacement program! Kit Contents:

Turner Motorsport Exhaust VANOS Hub Upgrade 4x Extended Length Hex Head Bolts (M6x30 Gr. 10.9) 8x OEM BMW VANOS Hub Hex Head Bolts (M6x25) 12x Fillister Head Torx Screw (M6x16) OEM Valve Cover Gasket OEM VANOS to Cylinder Head Gasket