Engine overheating and knocking

I suspect the overheating has caused internal engine damage. Here is a guide that talks about some of the symptoms of overheating:

https://www.2carpros.com/articles/symptoms-of-an-overheating-engine

I would suggest getting a recording of the noise and posting it and we can tell for sure if this is a internal engine noise.

Based on the noise, it is most likely loosing compression as well. If you would like to perform a compression test, here is the process:

https://www.2carpros.com/articles/how-to-test-engine-compression

However, from what it sounds like I am pretty sure you have internal engine issues so if you continue running the engine it will fail and you will need to replace the engine. Even if it doesn't fail and it is making noise, you are most likely going to have to rebuild or replace the engine anyway.

Sorry for the bad news but I am sure this is what we have. Thanks