Replacement BMW Serpentine Drive Belt Hydraulic Tensioner Pulley for BMW E46 E36 E39 X5 E53 Z4 E85 E86 | Part No. 11281748131 11281726343

Restore Belt Tension & Eliminate Noise – BMW Hydraulic Drive Belt Tensioner

Keep your BMW’s serpentine belt system in top condition with this direct replacement hydraulic belt tensioner, designed specifically for inline-6 engines. Over time, factory tensioners wear out from constant pressure, heat, and vibration—leading to belt misalignment, squealing, or even total accessory failure.

This OEM-style replacement restores proper tension to your serpentine belt, ensuring reliable operation of critical components like your alternator, power steering pump, and water pump. It’s a must-replace item during any belt service or cooling system repair.

• Designed for Hydraulic Systems – Not compatible with mechanical tensioner setups
• OEM Fit & Function – Matches factory part number for precise installation
• Reduces Belt Slippage & Noise – Restores proper alignment and tension
• Essential Preventive Maintenance – Replace with your drive belt for long-term reliability

FITMENT: Compatible with BMW inline-6 models using hydraulic belt tensioners, including: 

• 3 Series — E36 (318i/318is/318ti, 323i, 328i, M3); E46 (323i, 325i/xi, 328i, 330i/xi, M3 S54).
• 5 Series — E34 (525i); E39 (525i, 528i, 530i); E60 (525i, 530i) on M54 years.
• 7 Series — E38 (728i, 728iL – M52/M52TU markets).
• X Models — X3 E83 (2.5i, 3.0i – M54); X5 E53 (3.0i – M54).
• Z Models — Z3 E36/7, E36/8 (2.3/2.5/2.8/3.0, M Roadster/Coupe S52/S54); Z4 E85/E86 (2.5i/3.0i, Z4 M Roadster/Coupe S54).

ENGINE FAMILIES COVERED:

• M50 / M50TU, M52 / M52TU, M54, M56, S50 (US), S52 (US), S54 main drive belt pulley (water pump / alternator / PS). Does NOT fit N-series (N42/N46/N52/N54/N55, etc.).

DOES NOT FIT: 

• (N20/N26/N42/N46/N52/N54/N55, etc.), this pulley does not apply.
• For E60 525i/530i, ensure it’s the M54 years (early production/market-specific). Later N52 cars use a different pulley.

IMPORTANT NOTES: 

1. Centered Bolt Hole Design – This pulley features a centered bolt hole. If your factory pulley has the offset mounting hole, you will need part number 11287841228
2. Clockwise Rotation Only – Designed specifically for vehicles with a clockwise-rotating power steering pump.
3. For Hydraulic Tensioner Systems Only – Not compatible with vehicles using a mechanical belt tensioner. This pulley is intended only for models equipped with a hydraulic belt tensioner setup.

Replaces OEM Part Numbers: 11281748131, 11281726343 and superseded 11287841228.

Please refer to the “Fitment” section in the product description for compatibility details.