Loud embarrassing noise

You're going to have to make a few more posts before you're able to attach an attachment.
You may want to consider not driving the car in the meanwhile and you should check your coolant and oil levels much more regularly - especially the coolant level.
The 'Prius Death Rattle' is more of a 'knocking' than a screeching, but screeching usually isn't good!!!

If you do not know what the Prius Death Rattle is, you need to look into it fairly soon - as in immediately.
Enter that phrase into the search bar and you will get about 4 pages of results.

You also need to check your oil and coolant levels every time you fuel the car AT LEAST.....for now anyway.

Good Luck!

 

You need to use the 'Advanced Search' and limit your search to search only the 'Gen 3 (2010-2015) Toyota Prius Forums'; also tick the 'Search child forums as well' checkbox. This will cut down search results to your generation Prius.

 

Never heard that sound before. On the bright side the engine sounds ok. See if you can find the exact location it's coming from by putting one end of the stick on various parts in the engine compartment and the other end of the stick up to your ear.

 

Website-based search engines are terribly innacurate. It's best to use your preferred online search engine with key word 'priuschat' if you want to get a thorough list of all articles on PriusChat. Of course this noise, which sounds a bit like an air powered impact driver, isn't something I've ever read about on here.

 

I wouldn't go as far as to say inaccurate, but using the advanced search as I recommended goes a long way to cutting down on irrelevant results. I do recommend using a search engine from time to time as well. I personally have to resort to that infrequently so it is not in the forefront of my mind. Including the extra keyword 'gen 2' or 'gen 3' helps cut down irrelevant posts from other gen forums, in my experience.

As for the sound the OP posted, I have nothing to offer as I have no Gen 3 experience.

 

Now that Google has bailed on being a sophisticated search service and sold out to spew ads for almost every question asked, it's about time to create a new effort to do way more than ever to help people... Maybe we start organizing and work with owner Danny to create the next iteration of PriusChat? Maybe a link on website called: "Need Diagnostics Help, Click Here" and have that go to an AI system built on PriusChat data?

 

During this crazy noise is your air conditioner on inside of this vehicle or the defrost something running the air compressor that almost sounds like high pressure freon being forced out to high pressure relief valve