I have a 2004 Dodge Ram 1500 with a 4.7L magnum engine. She has 10700 miles on her I have replaced the thermostat, flushed the coolant, bled the air vent, installed a new water pump and everything is topped off with coolant. Now being summer here on the gulf coast in Alabama, I find lately my temperature gauge likes to creep up about 2 needle widths past the center line (not much) when it is at idle or at a stop and it has been running for a while & AC on and its 90 degrees outside. Normally the needle stayed just below center when she was new.  No engine codes or lights. Is this something I need to be worried about?   How do I know if the fan clutch is going out or the radiator is clogged?