I have a 2000 honda prelude that likes to overheat or try to, the dummy gauge is kinda everywhere from middle to almost to the H on the gauge back down...

I replaced the thermostat today and didn't change anyhing, no leaks, radiator and overflow has coolant in it.

I did notice the lower rad hose is stone cold when the top is hot after 20 mins of driving. My radiator fans do not kick in either. There is no white smoke or any smoke for that matter out the tail pipe.

Any thoughts?

I am leaning towards water pump or maybe a clogged system. Going take the rad cap off tomorrow and let it run see if I can get some air out.