What could cause a whining noise in my Honda Accord engine bay?

[Paisley.L]

I’ve got a 2015 Honda Accord that’s been making a faint, high-pitched whining noise that seems to come from the engine bay whenever I accelerate. It’s not the belts, I checked those, and the power steering fluid is full. I’m just wondering if this could point to a failing bearing in one of the accessory pulleys or something else I should look into before it gets worse.

[JerryM]

Yeah, that kind of whine often points to an accessory pulley or the alternator bearing. Since belts are ruled out and the PS fluid is fine, zero in on the front of the engine and listen for which pulley sounds louder as you rev.

[VioletGP]

I had a similar thing on my Accord years ago. It sounded like a high pitched siren when I stepped on the gas, belts were fine, and it ended up being the AC compressor clutch whining.

[MichaelL]

Sometimes a noise like that turns out to be something else entirely, like a loose heat shield near the exhaust or even a small exhaust gasket leak that only shows up under load.

[Richard.W]

Do you think the real issue might be something else like an exhaust leak, and not the pulley, or should I just chase the pulley theory?