My Supra has been sitting in the backyard waiting to get a new headgasket since July. I decided it was time for it to get put up in the garage for the winter, so I started it up and filled the radiator.
The temp climbed up to 75-80% on the gauge, and then...dropped. The heater was still blowing cold air, so I opened it up and added more antifreeze.
I took it down to get a cup of coffee and some more antifreeze, realized I had forgotten my wallet, came back home (only 4 miles round trip), got the antifreeze and filled the radiator some more, took it another mile and a half and filled the tires, then went back and got another cup of coffee, filled the raditor, took it for about 7 miles down a 50 MPH road, turned around, came back, then went about another 5-6 miles and back again. Never overheated (of course, it's also not 94 degrees...)ran the motor at different speeds, all the way up to 65 MPH; all in all the motor was running for about 2 hours and the temp was rock solid.
Guess all I needed was a new radiator...I hope. I have a head gasket just in case, but all in all I'm not sorry for not running the car because the suspension is WHUPPED and the U joints need replacing badly...