How to remove and replace a worn out idler (deflection) pulley on a BMW 330i (E46)

NOTE: You’ll need to loosen/remove the main Serpentine Belt to be able to remove the idler pulley Safely! This is done by releasing the force of the Tensioner Pulley.

Torque specs: 45nm (~33 ft.lbs.)

WARNING : BE CAREFUL when working on the Tensioner Pulley. There is quite a bit of force in this pulley!

Also, to make working on the idler pulley easier, I removed the Airbox, Upper radiator hose, Radiator Fan and Fan shroud to give myself some more room to work within.
These are not necessarily required removals, but they worked for me.
View the video DIYs here:
Airbox –


Radiator Fan & Shroud –

Please Note – Do this at your own risk. Follow all Safety Procedures. Wear Eye Protection! Wear mechanics gloves if possible. Not responsible if you break anything (Yourself or Property) End Legal Mumbo Jumbo Disclaimer.

This DIY was performed on a 02 BMW E46 330i automatic, alpine white paint, with Sport Suspension Package, you know the drill. So if that is not your vehicle, there might be differences.