Belt Tensioner Pulley 11287535860 For BMW E81 E87 E90 E93 E60 E61 E65 E66 E70

A tensioner pulley, also known as an idler pulley or belt tensioner, is a crucial component in a vehicle's engine system. It is designed to maintain proper tension on the belts that drive various engine accessories, such as the alternator, power steering pump, or air conditioning compressor. The tensioner pulley is typically a single wheel or roller that is mounted on a spring-loaded arm. It is made of durable materials such as steel or aluminum to withstand the forces and stresses encountered during engine operation.

The primary function of a tensioner pulley is to ensure the proper tension of the belts in the engine system. It helps to prevent belt slippage, which can lead to decreased performance of engine accessories or even engine damage. The tensioner pulley applies pressure to the belt, keeping it taut and ensuring efficient power transfer from the engine to the accessories. It also helps to absorb any vibrations or shocks that may occur during engine operation, reducing noise and improving overall engine performance.