Q: Loud noise from underneath car.

asked by on

Noise coming from underneath the car. It is so loud that attendants at a drive through window found it hard to hear my order. It's been doing it for a while, but the car runs fine.

Hearing any noise coming from your car can be startling, but it can be especially so when that noise is so loud others cannot hear you! Though the information provided is a bit limited, my experience tells me that the noise you may be hearing may be due to a leak in your exhaust system.

As vehicles age their components will naturally wear out and when you add the extreme heat of the engine to the equation, it is only a matter of time until one of those parts completely fails. Now if your vehicle seems to just sound louder in general, then it is likely your car either developed a hole somewhere in the exhaust system or the exhaust gasket itself has failed. When a failure happens, it will allow exhaust gases to prematurely escape the engine bay by bypassing the muffler. This is what you are hearing when you are aware that your vehicle sounds louder.

However, if instead you hear a clanking noise, such as a couple of quarters in a coffee can being occasionally shook around, then it is possible the material inside a component known as the catalytic converter, or even your car’s muffler itself, is failing and breaking down. When this happens the materials inside these components tend to break off in chunks and sit at the bottom of the muffler/catalytic converter and bounce around. This could also be the noise you and others are hearing.

As you can see, without actually hearing the noise it is a bit difficult to narrow down the issue to one diagnosis. Your best bet would be to next contact a certified mobile mechanic to not only use their mechanic’s ear to narrow down what you are hearing, but also inspect your entire vehicle for safety.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Loud noise from underneath car.

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: Car accelarates to 3000 rpm in park or neutral.

The throttle position sensor (TPS) is most likely failing. Air leaks in the intake can also generate a high idle, but not usually this high. If you need to have this checked, have a local mechanic, like one from YourMechanic,...

Q: Q: service engine soon

There is a TECHNICAL SERVICE BULLETIN for the problem and need to reprogram the PCM to a new level. The code is for a cam sensor signal being misread by computer and this TSB needs to be done before replacing...

Q: Mechanic changed cambelt and water pump and whilst returning it, it supposedly jumped off. Engine stopped dead. No more engine

Hello. I hate to say this but it is his fault. It sounds like he is not being truthful about what happened because if that was the case it would have come off well before he worked on it. It...

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...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.