Saturday the engine overheated, when I was driving (delivering meals - so stop & go - and it was a hot day, about 90°F), the guage came up to the red zone, then went to 0 then came back up quickly to the red zone, and first the engine coolant lite came on, then the electronic throttle control lite. I got back home, let the engine idle with the heater on full - but it was blowing cold air. I shut the engine off for about an hour, when I went out again and started the engine. the guage was at 0, and the etc lite was off, I drove it around the block, within a 1/2 block the temperature gauge came up to the red zone, the temp lite came on & then the etc lite again. I parked at home, the guage went back to 0 and the electronic throttle control lite came on again. I looked under the hood on Sunday after letting it cools and and couldn't see any problems. So I started to pour in antifreeze, and it ran out the bottom of the tube, so I thought maybe I blew the top rad hose. I ordered in new hoses, figuring if the top one blew, I might as well replace the bottom one as a preventative measure. It turns out, the top rad hose didn't blow - it looks like a plug blew out on the rad fill tube. Can someone confirm that it was a plug/cap or is it something more serious.