2005 Toyota Prius, Grinding Noise when Accelerating after a Complete Stop

I have been hearing this “grinding” noise in my 2005 Toyota Prius. It only occurs when I begin to accelerate from a complete stop (or a rolling stop), and typically occurs at 5 mph - 15 mph; This happens when turning and/or going straight, but not every time. It is inconsistent, and some days I head nothing, other days I hear the sound. I began to hear this noise after I had the hybrid battery and water pump valve replaced.

I am the 2nd owner of this Prius and my dad has helped me make sure to take care of it (thanks dad!). Normal oil changes, etc. The previous owners rarely drove it as I purchased it in 2018 with nearly 45k miles on it. We did have it driven by Toyota service center mechanics to get their opinion on this noise. They said it could be the transmission (did not want to hear that!). We already tried changing the transmission fluid which ended up needing to be changed but did not stop the noise from occuring.

Please see my video I finally took of one of my recent drives. This particular day the video was filmed it was colder than normal for where I live—32 degrees at the time. I am not sure if weather has anything to do with the noise but I have noticed on the colder days it seems to occur more frequently. I have noticed it too in warmer weather but not as consistently.

Any thoughts? I researched a lot but I cannot find someones else's situation that sounds similar enough to mine. I can provide further info upon request! Thanks!

 

Yes, you could hear it if standing next to the car. I will have to check your second idea, thanks!

 

It is hard to pin down if acceleration feels slower when I hear the noise because I try to not accelerate at the moment I hear the noise (when it is really loud) so that I do not make it louder! But in the times where I did continue to accelerate with the noise going, acceleration seemed normal. I will try and check your second point! Thank you!