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: Would a blown coolant hose, at heater core, cause loss of power?

Yes, severe overheating will cause loss of engine power and also has a high potential to damage the engine as the pistons scuff the cylinder walls and the exhaust valves stick in the valve guides. If the overheating is severe...

Q: Battery saver system car won't turn and battery good and starter. Whole dash illuminates when I turn key though, no alter

Have the battery load tested in case it was short circuited. Reverse polarity, at the battery, in a 12 volt electrical system on a car can cause a variety of effects including damaging the alternator, diodes and the numerous microprocessors...

Q: My car doors keep unlocking and locking after I turn off the car and it drains my battery. What do I do?

Hi there. Check all of the door switches on the door jams. The driver door or passenger front door will cause the doors to unlock after locked if the switch is not working. This is like the driver door open...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.