Very Faint Engine Knock at 2,000 RPM
 

Hey all--it's been a while. Hope everyone is doing well. Been getting a slight knock around 2K RPM when accelerating then goes away. Doesn't knock any other time. I use the highest octane. I'm only at 104K miles. I rarely drive so really don't need to take it to my Indy it seems. Thoughts on what it is? Thanks.