Cranks are fine and tight. Seems to be coming from within motor housing on the crank axis. Intermittent but frequent. Every minute or so. Does the spline need to be tightened? Anyone have an educated guess?
I had a similar noise to what you describe and it turned out to be the battery plastic moving against the frame when leaning the bike side to side when pedalling. A tiny bit of 3m tape sorted it!!!! I was convinced it was something mechanical but obviously there is some flex in the battery area.