Brief scraping noise under acceleration

[193290]

My 2017 CX-5 Touring AWD has been making a very brief and subtle noise when at slower speeds and applying the gas pedal. Usually happens if I let the vehicle coast for a second or two. I would describe it as a metallic scraping noise. Doesn't sound like grinding. Sometimes it's more pronounced and others its not. Usually happens at slower speeds below 40mph. It's always very short and when the accelerator is pressed.

I took the vehicle to a mechanic and they confirmed the noise, but said it would have to "break more" for them to do a diagnosis. They said something about heat shields, but I'm not sure if that could be the cause of this.

I've attached a video. The noise happens at the following timestamps: 0:11, 0:13, 0:15, and 0:17.

I gently pressed the gas pedal at each interval to reproduce the noise.

 

[RedBaron]

May just be me, but I don't hear anything above the engine noise.

 

[sgreer]

Did you ever get this figured out? I have the exact same year, trim and drivetrain as you and having the exact same issue. Slight grinding noise under acceleration, problem is exaggerated when gently pressing the gas pedal. Sounds like it’s coming from the drivetrain somewhere underneath the vehicle

 

[Mazdiod2]

I guess these kinds of noises can sometimes be explained by the slight movement of the drivetrain components because of the torque of the engine, or a heatshield moving and causing a sound.

If any of the gearboxes need lubrication that could be an explanation and with AWD there are several. The issues with lubrication are documented on this site.
So I would make sure all of the drivetrain components have been thoroughly maintained with fresh lube if that hasn't already been done. I believe there is a rear diff and the transfer case that can use an occasional drain and fill.

If there's something grinding and going bad internally, the mechanics might be right about waiting as eventually the problem could get much worse and the cause will be more obvious. And sometimes there's nothing you can do about it other than replace the component at some point. Of course if you wait too long you might lose warranty coverage, so I would keep 'listening' in case it gets worse.

I listened to the video a couple of times and maybe I could hear something at the designated time points but somehow recording from somewhere under the vehicle might be the only way to get a useful sound clip.

 

[ceric]

To debug this, divide-n-conquer.
Put your CX5 in Park. Rev the engine to see if you can reproduce the noise.
if not, it is the moving parts.. drive shaft, (incl. heat shield contacting it).
If yes, it could be engine mount, or tensioner slipping.