AC (indoor) making noise?

Worn or dry bearings in the fan motor produce a grinding or squealing sound that increases with motor speed.

Likely causes · most likely first

Fan Motor

Hard DIY Part: $40–$90
Cross Flow Fan

Hard DIY Part: $30–$70

A cracked or warped cross-flow fan wobbles during rotation, causing rhythmic thumping or rattling against the housing.
Air Outlet Stabilizer

Easy DIY Part: $10–$30

A loose or broken outlet stabilizer vane vibrates against the fan housing at certain airflow speeds, creating rattling noise.
Horizontal Discharge Grille

Easy DIY Part: $15–$40

Loose mounting tabs on the horizontal discharge grille allow it to vibrate against the casing during operation.
Bottom Frame / Drain Pan

Hard DIY Part: $20–$50

A cracked bottom frame allows internal components to shift and vibrate against the outer casing.

See the faulty part in 3D.

Tap a highlighted part to see exactly why it fails, how to verify it's the problem, and how to replace it.