Buzzing/Humming

Yes we get some sort of electronic buzz / whirr ...... sounds like something powering down. Not given it much thought

mrkjd said:

Yes we get some sort of electronic buzz / whirr ...... sounds like something powering down. Not given it much thought

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it could of been there all the time we have had the car, but never really notied it before,,

That must be the zoom zoom factor

I have been on our weekly trip in the car to the supermarket , and also noticed the noise whilst the car is running,
Currently stood 15 -25m away and the sound can be heard..
I have some sound files . But I'm unable to upload for some reason
But found this

I have exactly same thing as on the video, but one cannot here that unless the hood/bonnet is open. I had intentionally test driven two CX-30s after I noticed that on mine and guess what - same thing on all of them.

imnamak said:

I have exactly same thing as on the video, but one cannot here that unless the hood/bonnet is open. I had intentionally test driven two CX-30s after I noticed that on mine and guess what - same thing on all of them.

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... this is loud, you can hear it over the engine while sat in the car..

Something to do with the hybrid system? All my Lexus cars make a similar noise even before starting the engine. I just need to open the bonnet and it starts. Goes off after a short while.

just had an email from my dealer , they are opening next week after lockdown, so im dropping it into them for a listen,, my son who has the mazda3 same engine etc dosn't have any humming/buzzing...
sound like the fuel pump to me..

cx30 booked in next week at dealers, so they can take a look as they have not come across this problem before...

steve67 said:

cx30 booked in next week at dealers, so they can take a look as they have not come across this problem before...

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The first video is similar to what we see in above post, but this sound is not heard at all when the hood is closed, so its not annoying: here
Second one shows a "beep" sound, which can be heard in quieter environment, it goes up gradually then turns off then again up slowly and off from the moment you turn electronics in: here
I think that whatever you hear is the second sound, because the first one in my case was not heard unless I open the hood.

That high pitch noise in the video is normal as far as I know of the skyactive 2.5. It’s the throttle body servo that makes the noise. It shuts off after a minute or two. My 2015 3 has done that since day 1.

Drewmtb29 said:

That high pitch noise in the video is normal as far as I know of the skyactive 2.5. It’s the throttle body servo that makes the noise. It shuts off after a minute or two. My 2015 3 has done that since day 1.

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In my case both are constant and do not go away unless you completely turn electrics off. Those may be normal because all cars I tested had exactly the same thing.

just back from the dealers, yes the buzzing/ humming is normal, just very loud on my car, they showed me several orther cx30's all made the noise just at different levels/pitches..

Honestly, it does not sound and feel normal for me, but as you confirmed this is on all of them (you probably saw links to videos I attached few posts above), so I assume its OK.

i just wanted noted that tha car has been in for am inspection for the sound, just incase of problems in 18 months when i px the cx30

Sound in first post video is Normal, can be atmo temperature related, all Mazda's can/could do this it is not a fault....goes away after about 60 seconds, next door CX-3 does it (3 years old).
You may also hear on a stone cold engine start up a noise like car is running on 3 cylinders (fast idle) for about 60 seconds, again normal as this one is due to exhaust emissions and fast heat-up (engine lean out) of CAT.

ASH8 said:

Sound in first post video is Normal, can be atmo temperature related, all Mazda's can/could do this it is not a fault....goes away after about 60 seconds, next door CX-3 does it (3 years old).
You may also hear on a stone cold engine start up a noise like car is running on 3 cylinders (fast idle) for about 60 seconds, again normal as this one is due to exhaust emissions and fast heat-up (engine lean out) of CAT.

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It is normal..even though mine makes the noise all the time...🤔

The noise is the normal noise flap motor on the intake throttle body recirculating when you turn off the engine which is common to most Mazdas

steve67 said:

I have been on our weekly trip in the car to the supermarket , and also noticed the noise whilst the car is running,
Currently stood 15 -25m away and the sound can be heard..
I have some sound files . But I'm unable to upload for some reason
But found this

Click to expand...

Remove that engine cover. Place you hand on various items that do not rotate and feel for a vibration. If it's under other parts that could be hot take a piece of hose and place one end to your good ear and the other end gets moved around till you hear it at it's worst. If you can't place your hand on it place a screwdriver close enough to touch whatever you think it is. Show it to a tech or search the interweb. it sounds to me like a malfunctioning valve or a hose sucking air.