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 have should have mentioned the it also stop when you take your foot off of the gas pedal.
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 Skyactive-D has it as well. I hear it all the time when driving on highways.