Product Description

BMW N54 3.0L Twin-Turbo Accessory Belt Service Kit – OE-Supplier Continental Belt, INA Tensioner & INA Idler Pulley

Restore quiet, reliable operation to your BMW's accessory drive system with this OE-quality 4-piece service kit, sourced from the same manufacturers that supply BMW's production line. Engineered specifically for the BMW N54 3.0L twin-turbocharged inline-6 engine across E-chassis applications, this kit targets the most common causes of N54 belt noise, slippage, and accessory drive failure.

What's Included:

• 1x Continental ContiTech Serpentine Belt – 7PK1855 (BMW OEM# 11287628652)
Continental (Germany) is a confirmed BMW OEM belt supplier. The 7PK1855 is a 7-rib, 1855mm EPDM serpentine belt manufactured to exact N54 specifications. It drives the alternator, power steering pump, and A/C compressor. EPDM rubber construction delivers superior resistance to heat, ozone, and wear over older neoprene-based belts, with an extended service life. Note: the N54 uses an electric water pump and electric cooling fan -- these are not belt driven.

• 1x INA Belt Tensioner Assembly (BMW OEM# 11287563927)
INA (Schaeffler Group, Germany) is the BMW OEM supplier for the N54 tensioner assembly. This spring-loaded mechanical tensioner maintains precise, consistent belt tension across the entire accessory drive. A worn tensioner spring or seized tensioner bearing is the leading cause of N54 belt squeal and belt slippage -- and a failed tensioner can throw the belt entirely, disabling power steering, alternator charging, and A/C simultaneously. Replace at every belt service interval.

• 1x INA Upper Idler Pulley (BMW OEM# 11287556251)
INA-manufactured upper idler pulley with precision sealed bearing. The N54 routes the serpentine belt through three idler pulleys and one tensioner pulley -- the upper idler is the most commonly worn of the three and the primary source of bearing-related belt squeal. Engineered to exact OEM specifications for direct bolt-on fitment with no modifications required.

Important N54 Belt System Note: The N54 engine has three idler pulleys total (upper, middle, and lower) in addition to the tensioner. This kit includes the upper idler pulley -- the most commonly replaced. BMW specialists recommend inspecting all three idler pulleys at every belt service and replacing any that show roughness or play. Please verify which pulley(s) your vehicle requires before ordering.

Why the N54 Belt System Needs Attention:

• The N54 belt drives three critical systems -- alternator, power steering pump, and A/C compressor. A belt failure strands the vehicle and disables all three immediately.
• N54 idler pulley bearings are lifetime-lubricated from the factory. As lubrication dries out, bearings develop roughness and eventually seize -- causing the belt to shred or fly off the pulleys without warning.
• BMW specialists recommend replacing the belt, tensioner, and idler pulleys together every 60,000–80,000 miles. All components share the same labor access, so replacing them together costs nothing extra in shop time.
• Do not substitute a ribbed aftermarket pulley on the N54 tensioner arm. The OEM tensioner uses a flat-face pulley against a ribbed belt by design -- installing a ribbed-face pulley causes belt misalignment and rapid belt destruction. Always use OEM INA pulleys on this engine.

Why Choose This Kit:

• OEM-Level Quality – Continental and INA (Schaeffler) are direct BMW production suppliers -- the same parts in BMW dealer boxes, without the dealer markup.
• Exact Fitment – All components manufactured to precise N54 specifications for direct, no-modification installation.
• German Engineering – Both Continental and Schaeffler (INA) are headquartered in Germany and supply tier-1 components to BMW, Audi, Mercedes-Benz, and Porsche.
• Eliminates Belt Squeal – Fresh tensioner spring, new bearing in the idler pulley, and a new belt address all three root causes of N54 accessory drive noise in a single purchase.

Compatible Part Numbers:
Belt: 7PK1855 | BMW OEM 11287628652
Tensioner: BMW OEM 11287563927
Upper Idler Pulley: BMW OEM 11287556251

Chassis Fitment Reference:
E82/E88 135i (2008–2013)  |  E90/E91 335i & 335xi Sedan/Touring (2007–2011)  |  E92/E93 335i & 335xi Coupe/Convertible (2007–2013)  |  E60/E61 535i (2008–2010)  |  E63/E64 635CSi (2008–2010)  |  E71 X6 xDrive35i (2008–2012)

Fitment Note: Please verify compatibility using the fitment table above before purchasing. Always confirm your engine code is N54 (not N55) -- these engines share several chassis but have different belt systems and part numbers. If you have any fitment questions, please message us through eBay before ordering.