Rattling Underneath the Car
Schedule a Visit — Urgency 3/5Safe to drive in most cases. A loose heat shield is annoying but not dangerous. If the rattle is accompanied by a strong smell of exhaust fumes inside the car, or if the exhaust is visibly hanging lower than normal, get it checked straight away. This is general information only.
This is general guidance. Your situation may differ — when in doubt, don’t drive.
What does it sound like?
A tinny rattling or buzzing noise from underneath the car, often most noticeable at certain engine speeds or when idling. It might sound like a loose tin can or a vibrating metal sheet.
What could be causing it?
It could also be a loose exhaust mounting bracket, a cracked exhaust manifold, or an internal baffle breaking loose inside the silencer (muffler). Catalytic converter problems can also cause a rattle from loose material inside.
What should I do right now?
Get it looked at within a couple of weeks. A loose heat shield is a cheap fix — a mechanic can re-weld it, clamp it, or remove it if necessary. If it is a more significant exhaust component, they will advise on repair or replacement.