Q: Loud noise from underneath car.

asked by on January 12, 2016

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.

Catalytic Converter Replacement $291.63 - $3214.07 Get a Quote
Car is making a noise Inspection $79.99 - $99.99 Get a Quote

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.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Gas odor

It sounds like the evap vent is clogged near the fuel tank. This will cause the excessive pressure build up of pressure and the canister vent can get blocked with debris. Have this system checked and repaired as needed. ...

is it possible to put crankshaft sensor where canshaft sensir goes, and visa versa?

For the question as to whether or not you can put the camshaft and crankshaft sensors into the wrong orifice, I don't see this being possible. The physical dimensions would be close, but the protrusion of the sensor pickup should...

Oxygen sensor Bank 2 Sensor 2 for a 2008 ES350. How much to Repair and Replace?

Hi there. The Oxygen sensors are located on the exhaust system in front of the catalytic converter and behind the catalytic converter. You will need to have a Oxygen sensor socket to remove the sensors. The socket is a deep...

My engine is vibrating - 1999 Ford Windstar

An engine vibration can be caused by a few different components. You will want to start with the basics and that includes fuel, spark, and air. Check the spark plugs, wires, and distributor. These will all have a huge effect...

Truck is not getting fuel until holding the ignition in for a few seconds.

You may very well be on the right track with this and you should check the control module to be sure. You may also want to check the fuel pressure regulator as well to be sure you are getting enough...

Noise coming from front left side of engine.

Hello. Most of the time when this noise occurs from this engine, it is a timing chain problem. To isolate this, I usually remove the engine drive belts and run the engine to see if the noise disappears. If it...

How do i get the ignition cylinder back in the steering column?

When you went to put in the lock all you had to do was turn the lock cylinder to the key on position, then the pin would push in and slide it into the column. Once that is done, you...

Car makes a "humming" noise when I try to start it

Hello. If you were to tap anywhere, it would probably be the starter solenoid, which has the main power wire attached to it, although it is not likely that tapping the starter solenoid will start the car. It sounds...

How do I use shuffle mode when playing music off of a USB drive?

Shuffling songs is the same on your USB drive as it is when you use an iPod with a USB cable: Rotate the Menu or Menu/Sel knob until it highlights Shuffle Songs, then press the knob. Use the Menu...

Related articles

The Best Used Cars to Buy If You're a Farmer
If If you're a farmer, you know that what you need isn’t a used car – it’s a used pickup truck. How else are you going to haul around hay, implements, garden produce, fertilizer, and all the other things you...
A Buyer’s Guide to the 2012 Chevrolet Suburban
The The 2012 Chevrolet Suburban offers large amounts of space to carry around a growing family or to transport supplies to your favorite camping spot. It is available in heavy duty and half ton models. Key Features The 1500 Suburban...
2012 Toyota Camry vs. 2012 Chevrolet Malibu: Which One Should I Buy?
Mid-size sedans are the perfect family vehicle; offering just enough space for you and a few kids, but not so much that a small family will feel lost in them. This class of vehicles is slightly larger than a compact...