Hi there,\n\nI noticed that I have this brown stuff on the outside of my coolant reservoir, under the cap, I guess? Not sure where it's from or what's causing it. See attached pictures. (I didn't remove the cap.)\n\nAny thoughts? Anything to be concerned about?\n\nMy coolant level seems to be normal. It showed at about 1\/3 above the MIN line of the distance between MIN and MAX (at morning cold temperature with engine off). \n\nThanks for the help!