Valve Cover Assembly

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.

The factory magnesium valve covers on the S65 engine are known for developing micro-porosity, corrosion, and persistent oil leaks over time. This material is highly susceptible to oxidation, leading to unsightly surface imperfections, weakened gasket channels, and sealing issues that a simple gasket replacement won't fix.

Upgrade to this high-strength aluminum valve cover, engineered as a direct-fit replacement for your aging OEM covers. Unlike magnesium, aircraft-grade aluminum offers superior durability, enhanced heat resistance, and complete immunity to the corrosion issues that plague factory covers. Whether you're refreshing a high-mileage M3 or seeking long-term reliability, this upgrade ensures a leak-free, worry-free solution for your S65.

This valve cover includes gaskets, bolts, and the oil separator for a comprehensive replacement.

Features:

Eliminates the common porosity and corrosion issues found in factory magnesium covers.

Helps maintain optimal engine temperatures and enhances long-term reliability.

Gloss red finish provides a much-needed boost in engine bay aesthetic.

Designed for an OEM-like installation without modifications.

Reduces the risk of oil leaks, ensuring a proper seal.

Resistant to oxidation and chemical exposure for a long-lasting clean look.