Please research about the specific kind of noise you are facing. It's confusing for others when we describe all engine noises as knocking. There are variety of noises like vibrating, pinging, ticking, cluttering, popping etc. For now, listen to the sound clip from my Dominar 400 and reply whether it's the exact same noise or not:


Note that it is pinging noise in my case and it's WAY LOUDER in person, I used a smartphone to record the sound and it automatically adjusts all frequencies so it might not sound as loud to you, keep your earphone or speaker volume very high to hear it correctly.