Hey all,

I need help identifying a new low pitched humming noise that seems to be coming from the engine. It almost sounds like a bus when it starts moving from a complete stop.

Please take a listen (particularly at the 2, 4, and 6 second marks) to this sound file https://sndup.net/w9wc/

- I am driving in a parking lot and take my foot off the gas in between those pronounced noises in the audio file. It is barely noticeable in park or at a stop. If I had my foot on the gas the entire time, the sound would be consistently there. That is, the sound increases as the gas is pressed more, to a point...
- The noise only seems to happen at very low speeds, so first gear or so
- It doesn't seem to affect drivability, although I do notice my shifting at higher gears/highway speed seem a little rougher lately
- 2012 FX35, 135k km, original owner, well maintained and babied, mostly city driving and short trips

Any insights or questions are very welcomed - please help. Thank you!

Edit: Hooked up my OBD2 reader and it's clean. See screenshot.

Is this car 2WD?
Start from a stop in 2nd gear and see if the noise persists. Try 3rd and 4th, test as many as you can specifically. Take note of RPM when the noise is present.
Does it happen only when you're accelerating, pressing the gas or flooring it? What about holding a constant speed, or coasting on a highway? What about when you're turning sharply during this?
Sounds like it could be an exhaust droning noise, or a mechanical issue in transmission/differential

Thanks fontana dan

ok, will need to do the gear-specific tests. Including RPM. but from what i remember, the RPMs don't seem to be unusual

by the way, the noise does still seem to be there in higher gears, but is higher pitched/less noticeable possibly cause the road noise is drowning it out.

The noise is there even when it is in Drive and my foot is off the gas, just very less noticeable. Same with Neutral. Same with Reverse.
It's loudest when foot is on the gas and in the 30-40 km/hr range then it drops off around 50 kph. It's not noticeable on the highway, again probably cause of the road noise, but my passenger says they can hear it.

Any chance it's a bad wheel bearing(s)? Someone has also mentioned transfer case or low transmission fluid.