Skip the auto shop - Our mechanics make house calls

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.

A: Hearing any noise coming from your car can ...

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?

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: How do I use the remote keyless entry (RKE) system to locate my vehicle?

The remote keyless entry (RKE) transmitter has a vehicle location feature to help you find your car. This system is particularly helpful if your vehicle is in a parking lot or garage surrounded by many other vehicles, and you can’t...

Q: 4wd engages but vehicle bucks like 4wd is slipping.

There is likely an internal issue going on within your transfer case. The most common cause of transfer case slippage is low fluid. I suggest that the transfer case fluid condition and level is checked. If the two wheel drive...

Q: Fuel Pump Swap on Rodeo Isuzu

If they look the same, it will likely work. Make sure you are checking the connector connection closely. They can look the same but may not be. Small differences can make the difference. Also, check the hose connection. Make sure...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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...