BMW E9X 335i Belt Idler Pulley 90mm OEM 11287557851

Restore smooth and reliable belt operation with this BMW E9X 335i belt idler pulley. This 90 mm deflection pulley guides and tensions the serpentine belt that drives key accessories, including the alternator, air conditioning compressor, and power steering system. INA manufactures this pulley to OEM standards, providing a dependable replacement for a worn, noisy, or damaged original component.

Over time, the pulley bearing can develop play, produce chirping or grinding sounds, or create uneven belt movement. A failing pulley may also contribute to belt misalignment and premature belt wear. Replacing the idler pulley during belt service helps maintain proper belt tracking and supports consistent accessory operation. The 90 mm pulley size is essential, so compare the original component and confirm fitment before ordering.

• OEM-quality INA belt idler and deflection pulley
• 90 mm pulley diameter for the specified BMW belt system
• Designed to guide the serpentine belt for smooth, stable operation
• Helps reduce belt noise, vibration, and uneven wear
• Suitable for replacement during preventative maintenance or belt repair

This BMW 335i idler pulley replaces BMW part number 11 28 7 557 851, also shown as 11287557851. It is commonly associated with BMW E9X 335i applications, including compatible 3 Series models equipped with the relevant accessory belt arrangement. Always verify the vehicle year, engine configuration, pulley diameter, and existing part number before installation.

Install this BMW serpentine belt idler pulley with the appropriate belt and tensioner components when inspection shows wear or when completing scheduled belt maintenance. A properly functioning pulley helps the accessory drive system operate efficiently and quietly. Choose this INA 90 mm OEM replacement pulley for a precise, durable solution to common BMW belt-drive problems.