I have a 2015 Prius V that has developed a strange metal rattling noise behind the drivers side dashboard. The noise erupts when going over any sort of speed bumps, etc. It sounds like something has slowly come loose, but it's behind the firewall and the dashboard, so I can't get hold of anything. Has anyone else had this?
Yep—lots of Prius v owners describe a “metal rattle behind the driver dash” that only shows up on speed bumps. It’s often not the dash at all but the front-left suspension or something on/through the firewall. Here’s a tight checklist (fast to try, cheapest first): Sway-bar (stabilizer) end link – left front • Most common. A worn ball joint rattles over small bumps and sounds like it’s in the dash. • Test: With the wheel turned full left, grab the end link by hand and try to wiggle; any play or clicking = replace (usually both sides). Strut top mount / center nut / bearing – left front • A loose center nut or failed top mount gives a metallic clack over bumps. • Test: Open hood, look at the left strut tower. Bounce the car; watch/listen. If the shaft jumps or you hear a knock right at the mount, inspect torque/mount. Brake caliper hardware – left front • Loose slide pin or missing anti-rattle clip mimics a dash rattle. • Test: Drive over a bump while lightly pressing the brake pedal. If the noise lessens/disappears, check caliper pins/clips. ABS hard lines or brackets on the firewall (driver side) • A broken plastic retainer lets metal lines tap the body. • Test: With hood open, hand-tap the lines and nearby brackets; add a bit of foam where a clip is missing and re-test. Wiper linkage under the cowl / cowl clips • Loose cowl fasteners or wiper transmission can tick over bumps. • Test: Press down on the plastic cowl while someone bounces the fender; if it changes, snug clips/bolts. (If needed, remove wiper arms & cowl to tighten the linkage.) Steering column lower U-joint / column bracket • Rare, but a slightly loose fastener can ping on bumps and feel “behind the dash.” • Test: Engine off, wiggle the column near the knee area; listen/feel for play. Check the pinch bolt in the engine bay, too. Parking brake pedal bracket (foot-operated) • Loose bracket/fastener = metallic chatter left knee area. • Test: Tap the assembly and neighboring metal knee panel; snug bolts. Inside-dash loose shield/bolt • Metal knee airbag shield or a small bracket can loosen. • Test: Remove the lower dash/kick panel by your left knee; check for a loose metal panel or floating bolt and add felt tape/foam where metal meets metal. How to narrow it quickly (10-minute driveway plan): Bounce test: One person bounces the left front fender while you listen at the strut top, the cowl, and then inside by the parking-brake/knee panel. Brake-pedal test: Roll slowly over a speed bump twice—once normally, once with light brake pressure. Change = caliper hardware. Hand-check: With the car safely lifted just enough, grab/twist the sway-bar end link; any click = replace. If you want, tell me which of these tests changes the noise and I’ll zero in on the exact fix/part next.
