Ok, let me start by saying this is really wierd......

Everything is hooked up on my car as it should be....I just changed the water/antifreeze and filled it back up, including filling the overflow tank half way. I put the cap back on as it should be and started the car. The top radiator hose got pretty hot fairly quickly, maybe within 2 minutes while all the other hoses were cool to the touch. I let the car run for about 15 minutes and watched as the temp gauge got up to about 220. All the while I had the heater on and set to HOT. For one, the radiator fan wouldnt come on until I turned on the A/C and it cooled the car back down....but what is really wierd/odd is the fact that the vents never blew warm air. But wait, theres more.......if I rev the engine just a tad while the heater is on, it would blow hot air, let off the gas pedal and back to cool air.

Could I have air in the lines somewhere/somehow? What would make it blow cool at idle, but warm while driving? If I move the slider to COLD it will blow cold A/C or just cool vent air. By the way, the overflow tank never pulled water out of it or put anymore into it. What's the deal? thanx.

 

I know you say everything is hooked up as it should be. It really sounds like you have a vacuum leak.
Either in the Climate Control **** or under the hood. I'm in the process of redoing someone elses crappy swap job on my new to me Camaro. I'm leaning towards a vacuum leak, because you say it starts to work when you rev up. Revving up increases vacuum...does it work while you're driving? Could also be a problem with your Fan's Temp. Control Switch.

Hope some of this helps. New to 3rd Gens, seasoned in problematic vehicles.