Where is the transducer mounted in the second pic? On the transom or up front? I see the speed is 3.7 so I assume the engine is running. Also, did you mean to say you had engine noise from the beginning. Engine meaning the big high dollar machine hung on the transom, not the trolling motor. If the trolling motor is not on and the noise is from the main engine then it could be ignition noise. Simple to find out buy just powering down from idle speed and turn off the engine immediately and watch the screen to see if the clouds go away. I assume you have the PC 11 cable with the choke inline (big ball in the cable). If not get one. You may have to install some ferrite chokes on the trolling motor leads and maybe even the cranking leads to the engine if noise is confirmed to be coming from there.