Q&A

 Master

You may have damaged the engine by letting the oil get too low. The engine may still run, but the knock is usually from bearings and journals running out of oil and being damaged. The most common knock is a piston rod journal knock that will get louder as you go to a higher engine speed, especially above 3000 rpm and under load, like when your are accelerating on to a freeway. The only real fix is to repair or replace the engine, both of which are expensive, I am very sorry to say. Good Luck and let me know if you need any more help or advice.

engine shot replace engine should never wait for engine to tell you via knock to check oil way too late at that point

I had the same problem and I used RESTORE engine and it work for me.