Skip the auto shop - Our mechanics make house calls

Q: Car makes a metal rattling sound when stepping on the gas. It has gotten worse over time?

asked by on

A few weeks ago, I noticed a slight rattling/ticking sound coming from the engine when I stepped on the gas. I would let off of the gas and it would immediately stop. Then I would step on the gas again and the car would accelerate normally with no unusual sound. However, I always seem to notice a burning smell around the same time all of this happens. Over time, the noise has gotten louder and more constant. Now I hear it when I first step on the gas and continue to hear it while my foot is on the gas. When I take my foot off of the gas, the sound slows and stops but the sound is heard every time I step on the gas now. The first few times I step on the gas while driving, I still get that burning smell that accompanies the sound. I scanned my car to see if it was kicking any codes and got nothing. On October 19th, I got my brake pads, rotors, the front left caliper, and the drive belt & drive belt tensioner replaced. Any Ideas as to what is causing the rattling? Thanks!

My car has 164000 miles.
My car has an automatic transmission.

Hi there:

There could be multiple issues causing the rattling noise when you accelerate on your Mazda 6 ranging from a loose bracket, to an exhaust pipe that is cracked or even the serpentine or drive belt system that’s causing these symptoms. It’s also possible that motor mounts are starting to show signs of wear. The only way to really know for sure what’s causing this issue is to have a local mobile mechanic complete a car is making a noise inspection.

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!
  • Home
  • Questions
  • Car makes a metal rattling sound when stepping on the gas. It has gotten worse over time?

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: Motor blowed up 1994 Mazda B3000

Hello - replacement prices can vary widely for a used engine from a recycler, or a used "Japanese Domestic Market" engine shipped from Japan. They have much more stringent emissions than the U.S., and very good condition engines are available...

Q: Car has problems when braking.

What you are feeling is likely the brake rotors are warped, as you suspected. The rotors may need to be replaced. The rotors can get warped when they get hot and then hit water or excessive braking. Have the brakes...

Q: Wobble when braking and speeds over 50 MPH

Hi there. This is typically caused by warped rotors. When the rotors are warped, the steering wheel will shake when applying the brakes. This is a common issue. I usually measure the rotors to see if they are good, but...

Related articles

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...