I took my rad out and had it sent in to fix the leak got it back installed it thought I would run it for a little bit to make sure it was fixed (and it's not still leaking) didn't put the fan back in yet seems to cool fine without it....of course I keep moving....that sounds above like a thermostat stuck closed...
and mine needs a new rad only 600 from GM.....plus the 80 I paid to fix this one which still leaks, they said bring it back we will try again I said gee I don't have the rest of my life to take it out and put it back in again..thanks anyway.