Replace four of the most commonly deteriorated factory plastic engine bay caps in a single kit with this precision CNC-machined 6061-T6 billet aluminum M-Style engine cap set, designed for BMW M52 and M54 engined E36, E46, E39, X3, X5, and Z3 platforms. The factory plastic oil filler cap, oil filter lid, power steering reservoir cap, and coolant expansion tank cap are all prone to cracking, discolouration, and fluid leakage as they age and are repeatedly exposed to engine heat. This complete four-piece aluminum set addresses all four failure points simultaneously — each component is engineered to OEM specifications, finished with a corrosion-resistant anodized surface, and designed to deliver a cleaner, more premium engine bay appearance alongside improved long-term reliability over the factory plastic equivalents.

Features:

• M-Style oil filler neck sealing cap – 6061-T6 aircraft aluminum with stainless steel locking tabs and anodized finish for rust and corrosion resistance
• Oil filter lid cap – 36mm hexagonal head for tool-free installation and removal, premium aircraft aluminum for greater strength and hardness than the factory unit
• Power steering reservoir cap – retains all factory specifications including dipstick and ventilation holes, 6061 aluminum eliminates fluid leakage risk from plastic deterioration, supplied with a new gasket
• Coolant expansion tank cap – CNC machined T6061 billet aluminum rated to 2.0 bar maximum internal pressure, fits over the factory cover for a cleaner finish
• Full anodized surface finish across all four components for long-term corrosion and heat resistance

Specifications:

• Condition: 100% Brand New
• Type: 4-Piece Billet Aluminum Engine Cap Set
• Material: 6061-T6 Billet Aluminum Alloy
• Surface Finish: Anodized
• Processing: CNC Machined
• Coolant Cap Max Pressure: 2.0 Bar
• Oil Filter Cap Head: 36mm Hexagonal
• Compatible Engines: M52 · M52TU · M54

OEM Reference Part Numbers:

• Oil Filler Cap: 11127509328 · 11121405452 · 11121743294 · 11128655331 · 11127500568 · 11127560482
• Oil Filter Cap: 11421744000 · O-Ring: 11421741000
• Power Steering Cap: 32416851332 · 32411128332 · 32410141427 · 32411128333
• Coolant Cap: 17111742231 · 17110152374 · 17111712492 · 17111712669 · 17117639022

Fitment:

• BMW 3 Series E36 323i · 328i M52 Engine (1992–1998)
• BMW 3 Series E46 325i · 328i · 330i (1999–2005)
• BMW 5 Series E39 525i · 528i · 530i M52 · M54 Engine (1997–2003)
• BMW X3 E83 2.5i · 3.0i M54 Engine (2004–2006)
• BMW X5 E53 3.0i (2000–2006)
• BMW Z3 E36/7 · E36/8 2.8 · 3.0 M52 · M54 Engine (1999–2002)

Compatibility Notes:

• Oil filler cap: compatible with 2-prong cap style only – will not fit aluminum valve covers, aftermarket valve covers, or B58/S58 engine applications
• Oil filter cap: compatible with M52 and M54 engine families only – confirm engine code before ordering
• Power steering cap: retains factory dipstick and ventilation hole specifications
• Coolant cap: fits over the existing factory cover – confirm related part numbers match before ordering

Contents:

• 1x M-Style Billet Aluminum Oil Filler Neck Sealing Cap
• 1x Billet Aluminum Oil Filter Lid Cap
• 1x Billet Aluminum Power Steering Reservoir Cap & New Gasket
• 1x Billet Aluminum Coolant Expansion Tank Cap

Benefits:

• Addresses four of the most common plastic cap failure and deterioration points on M52 and M54 engine applications in a single purchase
• Billet aluminum construction eliminates cracking, discolouration, and leakage risk associated with aged factory plastic caps
• Tool-free oil filter cap removal with the 36mm hex head – no filter cap removal tool required
• Power steering reservoir cap supplied with a new gasket – ensures a leak-free seal from day one
• Clean anodized finish delivers a noticeably more premium engine bay appearance

Installation Notes:

• Wear gloves during installation – cap threads are sharp and may cause scratching on bare hands
• Oil filler cap is compatible with 2-prong cap style only – not suitable for aluminum or aftermarket valve covers, or B58/S58 engines
• Oil filter cap is for M52 and M54 engine families only – confirm engine code before ordering
• Coolant cap fits over the existing factory cover – verify related OEM part numbers before ordering
• If unsure about compatibility with your specific engine or chassis variant, contact our team with your chassis code and engine code before ordering

Warranty:

• 12-month standard warranty from date of purchase
• Contact our support team for assistance with any issues