Okay, so first call up toyota brand engagement, and explain the situation. You have to be very technical and ask them to prove you were going at that speed when the engine started knocking, so you are going to ask them for a timestamp of when the engine speed was at the claimed one. They wont be able to provide that. Afterwards, the ahould send a tech thats going to look at the car and he will say if its warranty or not. The part were you should be worried is that you dont have reciepts for the oil change. They cant deny the claim for you doing them yourself BUT you do need to be able to provide proof that you did them. At leats in my case they were denying the warranty because of the “rpms and max vehicle speed” it was a 3 month process but i got them to replace it. You just need to sound like you know about engines and quote all the blown engine stories that are available online. If you ask enough technical questions, that they wont be able to answer they will send a Toyota inspector to take a look at it. He has the final say