Replacement BMW Serpentine Belt Idler Pulley for BMW E46 E36 E39 X5 E53 Z4 E85 E86 | Part No. 11281748130 11281738605

Prevent Belt Wear & Misalignment – BMW Serpentine Idler Pulley Replacement

Support your BMW’s serpentine belt system with this direct replacement idler pulley, engineered for inline-6 models with hydraulic tensioners. While the tensioner maintains proper belt pressure, the idler pulley helps guide and stabilize the belt, reducing slippage and ensuring consistent alignment around critical engine accessories.

Over time, the pulley’s bearing can wear out or seize, causing belt noise, vibration, or even sudden belt failure. Replacing a worn idler pulley is essential to maintaining engine efficiency and avoiding unnecessary strain on your alternator, power steering pump, and water pump.

• Guides the Serpentine Belt – Maintains smooth routing and proper contact with pulleys
• OEM-Style Fitment – Direct bolt-on replacement for a hassle-free install
• Reduces Noise & Vibration – Replaces worn or noisy bearings
• Essential Maintenance Item – Ideal to replace during belt or tensioner service

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

• 3 Series — E36 (318i/318is/323i/325i/328i/M3), E46 (323i/325i/328i/330i)
• 5 Series — E34 525i, E39 525i/528i/530i
• X Series — X5 E53 3.0i
• Z Series — Z3 (1.9/2.3/2.5/2.8/3.0, M Roadster/Coupé), Z4 E85/E86 (2.5i/3.0i, Z4M)

IMPORTANT NOTES: 

1. Offset Bolt Hole Design – This pulley features an offset bolt hole. If your factory pulley has the centered mounting hole, you will need part number 11281748131
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: 11281748130, 11281738605 → 11287841228 (supersession).

Tip: These are the common applications for this pulley family; always confirm by VIN before ordering.

BAVMODS Part No: BAV0000048A

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