2007 Prius - 95k miles - I'm getting a noise from the engine bay area - only when the gas engine is running. Video below searching the forums - this could be - 1) Wheels/bearings 2) water pump 3) belt/tensioner or 4) other? anyone have an opinion on what is causing this noise?
I also have a 2007. Unless somebody knows this outright, can you verify that when you coast, and the gas motor shuts off, this noise goes away? I know at highway speeds this probably doesn't occur, but how about a little more info, like the speed at which you notice the sound. Did it just start or progressively got louder over time/months? Rule out the wheel bearing.. Doesn't sound like a wheel bearing and nothing to do with the gas motor. I had a noisy water pump that I replaced. Noticed that racket more at idle and my experience was it sounded like a chain clanking. The water pump sound was overwhelmed by other road noises at highway speed. Never dealt with a belt tensioner issue, but that would be RPM based, so it wouldn't be much louder on the freeway. It sounds to me like some kind of electric pump, but my gut tells me something tire related. If its tire related I would't just think it started unless you picked up something on your tire. That would probably make a sound regardless of speed.
Just started - i was on a highway trip, and noise started while on the highway - noise has stayed about the same since then. no noise when parked at idle or in "maintenance mode" (where the gas engine is forced on). Noise is first noticed once i get over 15mph ish. Noise gets louder the faster i go, but then gets quieter - probably loudest around 40-45mph.
any check engine lights? Maybe just for ruling out the axles/wheels, does the noise change when you change the loading on the left and right side by gently swerving to the left and right at 40 MPH?
first i tried swerving in a parking lot at low speed - 10mph - i heard nothing. at a higher speed, i heard a little something at 40mph on the right side probably coming from the tire or breaks - but it was a different noise that before.
I am afraid I am stumped. I think you have ruled out tires and suspension, since the noise was constant. Hopefully this question will move its way back to the top and get some visibility. If you take it into service and/or find the cause, please update your post so people are made aware.
it was the front passenger side wheel bearing. They also replaced the ball joint. The mechanic took it for a test drive and diagnosed it quickly. After replacement, it's back to being very quiet thanks for the help
That makes sense for a highway noise. I have had two wheel bearings go bad. Both were passenger side. They both had pretty big changes to the sounds they made when shifting weight left to right to the point where they almost became silent on off ramps glad you got it repaired and thanks for posting the fix
Thanks for the post, I'm having the same problem right after I got mine, thankfully it isnt as loud as yours but still annoying.
