BMW S54 Billet Aluminium/Aluminum Water & Coolant Pump Pulley – E46 M3 (incl CSL), Z3 M, Z4 M E85/E86 – Direct-Fit OE Replacement Serpentine/Accessory Belt Drive Pulley – Hard-Anodised Upgrade

Billet Aluminium Coolant Pump Drive Pulley Upgrade for BMW S54

Replace the fragile factory composite pulley and strengthen your S54 cooling system with a CNC‑machined 6061 billet aluminium drive wheel. Hard‑anodised for corrosion resistance and built for long‑term reliability, this direct‑fit pulley tackles a known weak point on high‑revving M models and helps keep you on the road, on track and out of trouble.

Perfect for fast road, track day and spirited driving, it is a straightforward swap that retains the standard auxiliary belt path and factory hardware. If you are refreshing the coolant pump assembly, this is the ideal time to upgrade from plastic to billet.

Why choose this pulley

• Precision CNC‑machined from 6061 billet aluminium for strength and durability
• Hard‑anodised finish to help prevent corrosion and wear in harsh under‑bonnet conditions
• Direct replacement that works with the OE serpentine belt and original fasteners
• Improved confidence under high RPM and heat compared to brittle composite wheels
• Clean, OE‑plus look with performance‑grade materials

Compatibility - S54 3.2 straight‑six

• BMW M3 E46, including CSL
• BMW Z3 M Coupe and Roadster with S54
• BMW Z4 M E85 and E86, Coupe and Roadster

Direct‑fit details

• Uses the factory belt: BMW part number 11287837898
• Reuses original hardware: BMW part number 07119903843
• Simple swap for the stock plastic coolant pump pulley

Real‑world results

We have installed these for customers and the feedback has been excellent. Owners report peace of mind on track, reduced worry about cracking at high RPM and a smart, OE‑style finish that looks at home in the engine bay.

Ideal search terms

BMW M3 E46 pulley upgrade, S54 coolant pump drive, Z4M accessory belt pulley, Z3M S54 cooling system upgrade, E85 E86 M Coupe pulley, BMW performance parts UK, direct replacement OE spec pulley, track day reliability upgrade.

Professional fitting

Want it installed professionally? MJ Modifications in Warwickshire can help. Request a fitting quote at info@mjmodifications.co.uk.

Note: Product is a direct‑replacement coolant pump pulley and is designed to work with the OE belt and fasteners listed above.