Lately my truck has been getting very warm when at idle. It was rare at first but now is becoming more and more common. When I'm at idle mainly in a drive thru the temp gauge will slowly creep up and get to right up underneath the red in maybe 30-40 seconds. If I put it in nuetral and run it up to about 1500 rpms it will slowly go back down, but it gets annoying having to rev my truck in the drive thru <img src="/forums/images/graemlins/lol.gif" alt="" /> Do you guys think this could be a water pump starting to go bad or maybe something with the thermostat? Those are the only things I can think of. Truck has 84k on in it.

It will be one of three things; the radiator has mud and bugs clogging the air fins, the thermostat is sticking, or the water pump is going bad.

My guess would be the thermostat or the radiator being plugged. Thermostat would be my first guess, sounds like it might not be opening right away. Fix it ASAP; bad things can happen if it gets too hot.