FREPURDO Drive Belt Idler Pulley Compatible with BMW E36, E46, E9X M3, E60 M5, M50, M54, S52, S65, S85 Replace: 11281748130

While there's no strict mileage guideline, most mechanics advise replacing the idler pulley when the serpentine belt needs changing, typically every 60,000 to 100,000 miles depending on driving conditions. I have the original idler pulley in my E36 M3, so when I replace the serpentine belt, I will also replace the pulley. My existing one is quiet, although that in itself doesn't mean it's not worn down. A worn pulley will sound like it's squealing like a baby pig. A new pulley will have smooth movement with some resistance, while a damaged idler pulley will spin freely. From what I can tell, this FREPURDO Drive Belt Idler Pulley looks well-built and matches the OEM idler pulley.I chose this Drive Belt Idler Pulley as a replacement for my BMW E36, and it fits perfectly. This genuine BMW part is an OEM replacement, designed to work with several BMW models, including the E36 and E46, as well as M3, M5, and M6 models. It's made from high-quality materials that ensure durability and long-lasting performance, which is important for maintaining the tension on the belt and avoiding premature wear on other components.While I haven't installed it yet, I plan to replace the idler pulley during my next maintenance period when I swap out the serpentine belt. The pulley looks like a great fit, and it seems easy to install as it's a direct bolt-on replacement. I’m confident it will work smoothly and help keep the serpentine belt in optimal condition. Although my current pulley isn’t making any noise, I want to replace it preemptively to avoid any future issues. Based on its quality, I’m confident this will be a reliable replacement, and I’m looking forward to installing it soon. If you’re looking to replace your idler pulley on a BMW, this is a solid choice.