How long can you drive with a bad idler pulley?

Driving with a bad idler pulley can vary in duration depending on the severity of the issue, but it's generally advisable to limit driving as much as possible. A failing idler pulley can lead to belt misalignment, increased wear on the serpentine belt, or even belt failure, which can cause engine overheating or loss of Power Steering. If you notice unusual noises or performance issues, it's best to address the problem promptly to avoid further damage. Ideally, you should have it repaired as soon as possible.