What’s causing a squealing belt, and could a faulty tensioner be the cause?

[Aubrey93]

I think my car’s serpentine belt is starting to squeal, but only when it’s cold and damp in the morning. It goes away after a few minutes of driving, and I can’t see any obvious cracks on the belt itself. I’m just not sure if this is a sign it needs immediate replacement or if something else like a tensioner could be causing the noise.

[Kevin71]

That sounds familiar. The serpentine belt can squeal when it’s cold and damp and then quiets as it warms up. It might be moisture slipping for a moment rather than a worn belt. Still a quick glance at the belt edge for glaze or tiny cracks is worth it.

[AriaS]

In my case it was the tensioner bearing going bad. The squeal showed up only at first start, and swapping the tensioner (and belt) stopped it.

[PaisleyM]

I'm not sure it’s the belt at all. A stubborn pulley or misalignment can mimic the sound, especially when the system is cold. If you don’t feel the belt slipping, it could still be worth a mechanic look, since a cheap fix now saves a wobble later.

[Natalie_J]

Have you had it inspected yet?