I drive a Skyactiv 2013 Mazda 3 2.0 Liter MT 65,000 miles, and recently bought a 2023 CX-5 NA AT bought new, now at 10,000 miles. Over time I noticed pretty much the same noise with the same characteristics in both vehicles. I get to maybe 45 MPH ish, and I hear a whine that slowly raises in pitch with speed.
Both cars drive perfectly normal. Seems unlikely that it’s an issue since both cars do it. I’ve read a post or two where people took their cars to the dealership and they said it was a normal sound that the alternator makes. Interested to see if anyone else experiences this with their car, or has any thoughts on it.
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I remember reading a bulletin regarding transmission whine for 2014-ish automatic transmissions as being an uncorrectable defect which did not affect its performance nor reliability. So basically the TL;DR was “just deal with it”
I have should have mentioned the it also stop when you take your foot off of the gas pedal.
My Skyactive-D has it as well. I hear it all the time when driving on highways.
This suggests that it’s something on your serpentine belt, such as the alternator or ac compressor bearing or the tensioner pulley.
What makes you say that, just out of the interest of learning? Also planning on changing out both belts and tensioner for routine maintenance on the 3 soon, so that’ll be interesting to see if anything changes.
If the noise occurs under load and instantly stops when you take the load off, that’s often a sign of something on the belt. Can be a sign of transmission issues too. Actually it occurs to me to wonder if you’re hearing the normal sound of a six speed auto transmission found in both cars? Because the fact that you hear it on both vehicles suggests it isn’t a mechanical problem.
Just replaced both belts and the tensioner on my 2014 3 at 150k miles. Didn’t really hear any change in sound though.
What about the timing adjustment tied to acceleration? Something Mazda is famous for doing?
Can’t be too famous since I have no idea what this means and I’m a decent mechanic.
My 23’ N.A. does it. Sounds like a turbo spooling up so I like it.
My 2011 Mazda2 does not. The only sound it makes that I’d classify as a whine is first gear and reverse, which I assume is from those gears being straight cut or at least less helical than the rest.
Yeah from the sound of it, it’s the electric motor used in the timing system that would only be on Skyactiv engines
Can you produce a sound clip of the whine?
I’ll leave a recorder going on my drive home tonight, but it’s probably too quiet.
As I increase speed I also hear a whine. But in my case it’s my wife.
My 2013 Mazda 3, with the Skyactiv 2.0L also has a very slight whine when driving. It’s pretty much always had it since I bought it at 40,000 miles, (Currently at 209,000) It hasn’t stopped running yet. I notice it’s a bit louder when it’s cold and as the car warms up it gets much quieter.
Mazda technician here. Couldn’t say for absolute sure that what you’re talking about is normal without hearing it for sure, but I can say every skyactive-G engine has a whine once you get past around 25 miles per hour. 100% normal and happens on brand new cars even.
Awesome thanks for the response, is it normal for just the Skyactiv G or other Skyactivs as well?
I also have a faint whine on the skyactiv x on a 2021 mazda 3. It usually happens when accelerating hard at speeds higher than 40 miles per hour. To me it never sounded like something wrong but rather as a particularity of the engine.
My CX9 got a distinct whining like sound around 53-54 mph.
Alright. I can’t believe no one’s said this yet.
The timing system uses an electric motor to advance/retard the timing on the intake valves. That’s why it sounds like an electronic noise and not a gear noise. This is also why it seems to increase in pitch as you increase RPMs. When the engine is under load like when you’re accelerating, it’s adjusting timing to avoid knock. That’s how the high compression on the skyactive is achieved.
This is just how they sound. My 2.5 NA sounds exactly like you describe.
This makes a ton of sense, do you know if that’s in every Skyactiv engine or was it introduced in one of the revisions?
I’ve never noticed that, but if anything, it’s probably the transmission.
It’s either the fan, or the headlights.
The fan makes sense, but how would the headlights make that noise?
I think they have their own cooling fans. Def a high pitched whine.
Not on his Mazda3 they don’t.
Ahh strange, but not surprised with how bright headlights are nowadays I guess. Might still be something else with the variation in pitch with speed and the fact that it also happens on my gen 2 Mazda 3.
But the cooling fan itself I could still totally see being it.
My headlights have cooling fans?!? Man tech moves so fast
Yeah crazy, makes it make more sense why modern headlight fixtures cost so much to replace.
Do others hear this same nose?
Have you had your heading checked?
Do you possibly have tinnitus?
Yeah my girlfriend hears it as well.
Can you elaborate on having my heading checked?
And I do have tinnitus (been working in the live music industry for a while around a lot of loud noises), but that’s a stable Bb pitch that I’ve been hearing for a decade, and this is something that raises in pitch with speed.
He definitely meant hearing lol
Lol that makes more sense, I have though lol. Ive been working as an Audio engineer for a bit now, so I’m pretty paranoid about that stuff
Wheel bearings starting to go ??
Good guess, but probably not. low mileage vehicles and only really noticeable at somewhat higher speeds. Also hasn’t gotten any worse over 1000s of miles.
From some other comments it sounds like it’s the electric motor in the engines timing system.