On my new 350h I periodically hear a low "hum" when driving and sometimes sitting. Do other 350h owners hear the same thing and it is just a characteristic of the hybrid. It is very low and barely noticeable but it is noticeable.

 

When using the seat coolers a fan sound is noticeable. Could that be what you hear?

 

No sounds like something from the motor. I will try to turn off all the blowers though and give a drive to see if it is some fan noise. Thanks for the tip!

 

That sound drove me nuts for weeks before I figured it out. 🤣

I can almost bet that's the noise you're hearing. It's quite loud and disorienting at first, but once you know what it is, it's easy to tune it out.

 

When the 350h is running electric only and below a certain speed, it broadcasts noise so others can hear you coming. The manual call it the "acoustic vehicle alerting system." Could that be what you're hearing?

 

Normal sound when car running in EV mode and under 25-30 mph to alert pedestrians to your presence. Federal regulation requirement for EV/hybrid cars.

 

Thanks for the posts jgr and Cang. That electric "noise" might be what it is. When I get the chance I'll have to take it out and check to see if that is it. Thanks for the tips.