ej2five

I cant tell if the noises my engine is making is a knock or just the normal noise of a boxer 4 cylinder. This is my first ever Subaru. Its a 98 Legacy GT with the EJ25 Naturally Aspirated engine in it. The engine had a rebuild roughly 45,000 miles ago. I just recently bought it. There also is a humming noise coming from the engine, don't know if its oil pump or water pump or what. https://www.youtube.com/watch?v=gpnJbv5yask