What could cause a high-pitched whine in my Honda Accord from pulleys?

[Olivia91]

I’ve got a 2015 Honda Accord that’s developed a faint but constant high-pitched whine from the engine bay. It seems tied to RPMs, not road speed, and it’s there whether the car is in gear or just sitting in park. I’ve checked the serpentine belt and it looks fine, but I’m wondering if it could be one of the accessory pulleys or maybe the power steering pump starting to go.

[Camila69]

I had a similar high pitch a while back. it followed the engine rpm more than road speed. the belt looked fine so I poked at each pulley with a long screwdriver just to listen and see if any bearing sounded rough. nothing obvious showed up so I kept driving and hoped it would go away. a week later the noise stayed and the shop said the alternator bearing was the culprit. I am not saying yours is the same but it did make me consider pulleys and the belt path.

[AdamH]

could be the power steering pump starting to fail but I would not rule out a worn tensioner or pulley. when mine did it the noise grew louder as the engine worked harder and quieter when I eased off the gas. I would try to isolate by listening near each pulley with a stethoscope and noting which one sounds the worst.

[EvelynIL]

could it be the alternator bearing or the water pump bearing?

[MadisonAA]

another tangent I chased was a loose heat shield around the exhaust. that can make a faint high pitch that sort of climbs with rpm too. I dropped that line and stuck to the belt side and still did not get a clean answer.

[Hannah88]

im not sure this is the real problem but I would try turning on the ac and listening if the tone changes when the compressor clutch engages. if it stays the same maybe a pulley or bearing behind the belt is the issue. either way I kept driving and watched for wobble rather than waiting for a perfect fix.