I have a 2013 G37 iPL and it overheats when it’s driven on a hot after noon or when the a/c is turned on, even when’s it’s colder at night if the a/c is on it’s going to over heat and recently replaced the radiator, thermostat and the radiator cap and thought that would but it’s still over heating, I looked at the radiator and saw this weird spray of oil can someone advice me what it is and what I can do to combat this