What’s that noise?

Squealing when braking Usually the wear indicator on the brake pads Grinding when braking Worth stopping for Usually the pads are gone and metal is running on metal Clunk when braking Usually worn caliper hardware or loose brake pads shifting in the bracket Clicking when turning Usually a worn cv joint, usually on the outer end of a driveshaft Groaning when turning Usually low or old power steering fluid, or a failing pump Grinding when turning Worth stopping for Usually a wheel bearing, which usually also hums at speed Clunking over bumps Usually worn sway bar links — by far the most common cause and one of the cheapest to fix Rattling over bumps Usually a loose exhaust heat shield, which rusts at the edges and vibrates Knocking when accelerating Worth stopping for Usually detonation — the fuel igniting unevenly, often under load or up a hill Whining that rises with the engine Usually a failing belt-driven pulley or tensioner bearing Roaring when accelerating Usually an exhaust leak, often at a gasket or a rusted joint Rapid clicking when starting Usually not enough current reaching the starter — usually the battery or its connections Grinding when starting Usually the starter drive not meshing cleanly with the flywheel ring gear Squealing on a cold start Usually a glazed or loose serpentine belt slipping on a cold pulley Humming at speed Usually a wheel bearing, which typically changes as you steer gently left and right Droning at speed Usually uneven tire wear, often from an alignment problem that has been there a while Ticking at idle Usually normal valvetrain noise on many engines, or low oil level on some Hissing at idle Usually a vacuum leak — a split hose or a perished gasket letting unmetered air in