Boy I wish I took pics of the amount of dirt, sand, and tiny organic material (pine needles ect) that I found when I took off coil cover. Today I had to correct the washers on the NEL coil on the TR. It was too loose so the coil moved sometimes on its own. I decided to remove the coil cover when I heard a little rattle inside. Turns out there was a ridic amount of caked on debris. I didn't think stuff would get between there but apparently it does. So this serves as a heads up to check and clean yours every once in a while. I have two machines with coil covers, but no hours on one machine so it's not gonna have any yet.