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Very faint high pitched "mosquito" sound

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2019 CX-5 GTR
It sounds like it's the same sound as discussed in the other thread.

- Loudest when engine is under load and starts around 2000 RPM. I don't hear it when the vehicle is parked and run up to 2000 RPM.
- Extremely faint at idle
- Sound varies proportional to RPM in that 2000-2500 band
- Much more noticeable when cold, get's real faint when engine is fully warm.

It's not a rattle.

I suspect it's the turbo, valve train or some other engine component that emits a resonant buzzing sound as a function of temp, rpm and load.

Has anyone asked the dealer to look into it? I'm afraid they'll say it's "normal". Do we have any Mazda tech's in this forum?
As Javila21 mentioned above, it's noticeable even at a complete standstill.

However, the sound increases at around the 30-40 mph area and then drops off when letting go of the accelerator.

The sound also comes back when you're breaking and about to come to a complete standstill.
 
I hear a high pitched faint "whitsle" under load in my GTR. I just assumed it was normal "turbo whine" where the turbo is spooling up.
 
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ss
As Javila21 mentioned above, it's noticeable even at a complete standstill.

However, the sound increases at around the 30-40 mph area and then drops off when letting go of the accelerator.

The sound also comes back when you're breaking and about to come to a complete standstill.
On mine, it's extremely faint at idle but still there. However I don't hear it when I open the hood and listen because the normal engine sounds drown out the faint buzzing.
 
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2019 CX-5 GTR
On mine, it's extremely faint at idle but still there. However I don't hear it when I open the hood and listen because the normal engine sounds drown out the faint buzzing.
The sound seems to be coming from the front when sitting inside the cabin.
 
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ss
Could this sound be coming from the speakers?
That thought had crossed my mind but I don't think it's the source. (why just the 2.5T?)

The sound is similar to radio noise in older cars when they picked up interference from the breaker point ignition system and that noise varied by RPM.
 
Cant be heard under the hood and its not coming from the speakers. Also not really there when reviving the engine in neutral. I initially thought it was coming from the HUD. However, After disabling it, the noise was still there.

My dealer is over 200 miles away. Otherwise I would have brought it in by now.
 
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2019 CX-5 GTR
That's Savage Geese's guess. See [or hear] this. [Noise at 16:22] Is that the noise?
Yes, that is very close to the sound I hear.

I watched this video before but I completely forgot about this part.

So, it's because of the fuel pump?

Will this become a problem later?
 
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ss
That's Savage Geese's guess. See [or hear] this. [Noise at 16:22] Is that the noise?
It could be it. It makes some sense since the direct fuel injection pump (not fuel pump) obviously varies it's output based on RPM and load and operating temperature.

Anyone know if 2.5T's have a unique fuel injection pump from 2.5NA's?

I'm also curious why CX-9 users haven't mention this sound? (same exact engine???)

If the theory is correct, it's probably similar to this. I'll see if I can find it and put a stethoscope to it.

It looks like there are articles on noise in direct injection fuel systems:
https://www.sciencedirect.com/science/article/pii/S1877042812030261

 
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sm1ke

Work In Progress..
Moderator
Contributor
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Canada
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'18 CX-9 Signature
I've been noticing it in my CX-9 lately. It only seems to make the noise when it's cold outside, and even then it's very faint. At first I thought it might be feedback from the USB charger, then I thought it might be speakers.

I'd head to my dealer to pick their brain but they're too far out of my way and I'm a little too busy with a sick 1-year old at the moment.
 
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2017 Mazda CX-5 GT + PREM Pkg 2019 CX5- GT Reserve
That's Savage Geese's guess. See [or hear] this. [Noise at 16:22] Is that the noise?
might be me, but I can't hear anything in the video. probably just my ear.
anyway now that I think about it my other cx-5 (17' GT) had almost the same sound but it was not as cricket-y as this one. it was high pitched but it just went away I believe after my first oil change.
 
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ss
OK, I opened the hood and found what I'm sure is the Injector Pump. The overall engine noise at idle masks the sound from the pump but when I place a long screwdriver on the pump housing and listen, (ie poor man's stethoscope), it makes a very noticeable ticking sound at idle. I'm 99% sure this is the buzzing we hear and the frequency goes from ticking to buzzing as RPM/load/pump output increases.

Mine seems to be getting more faint with mileage (about 2500 mi so far).

If anyone has a Mazda tech look into this please reply to this thread. I'm guessing Mazda will simply say it's "normal".
 
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2019 CX-5 GTR
OK, I opened the hood and found what I'm sure is the Injector Pump. The overall engine noise at idle masks the sound from the pump but when I place a long screwdriver on the pump housing and listen, (ie poor man's stethoscope), it makes a very noticeable ticking sound at idle. I'm 99% sure this is the buzzing we hear and the frequency goes from ticking to buzzing as RPM/load/pump output increases.

Mine seems to be getting more faint with mileage (about 2500 mi so far).

If anyone has a Mazda tech look into, this please reply to this thread. I'm guessing Mazda will simply say it's "normal".
If it's "normal" I guess we'll have to learn to live with the sound, as annoying as it is.

The concern is whether this is not normal and can possibly lead to problems later on.
 
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2014 Mazda CX-5 GT w/ Tech
I'm confused, you wanted a vehicle that had a HPFP and a turbo that spins as xxx,xxx rpms to be silent at speed?
Unless it goes through the normal level of music that I play or actually comes through the speakers (which some electrical noises are prone to do when bad)...
Or is this noise so loud that it literally shines through? Because even my friend's various Teslas are quiet but you can hear the electric motor whines if you try to listen for them...
 
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