Skip the auto shop - Our mechanics make house calls

Q: Car making rattling sound

asked by on

My car makes a rattling sound when I turn it on, like something is broken and rolling around.

The problem is likely the catalytic converter deteriorating. This happens over time, and the catalyst will rattle around inside the steel housing. The noise is loudest at start up or while revving the engine. With the engine off and cooled off, shake the tailpipe and listen for the noise. If you hear it, the noise is somewhere in the exhaust, most likely the converter as mentioned earlier. If you need assistance, a certified mechanic from YourMechanic can come to you to diagnose your vehicle’s rattling noise.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Issue with my A/C, what is the most likely problem?

Hi and thank you for contacting YourMechanic. Most likely what has happen is the blend door has malfunctioned and now when you switch to AC the door isn't moving and still allowing nothing but warm air to flow. You should...

Q: I have a new fuel pump and there is no fuel to the engine

Hello and thank you for contacting YourMechanic. A plugged-up fuel filter will cause an engine not not start. Get a fuel pressure tester and hook it up to the fuel rail. There should be a shrader valve on the fuel...

Q: Vibration on startup - 2013 Ford Focus

Hi there. From the description you have given, a tune-up may be in order. Short trip driving is harder on the engine, than long trip driving. Based on the low mileage, it is not due for the tune-up according to...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...