Mine was doing that a week ago, so I took it to the dealer. Long story short, they said they fixed whatever was wrong (can't exactly remember what) and about 15 miles into a trip later that day, my car stared over-heating. I pulled over and checked under the hood like anyone would do and I found that there was no coolant.
I had the dealer tow my car in cause I did not want to drive it just in case (knowing how my dealer is) and they said it was something to do with the radiator cap not releasing pressure or something or something with a faulty radiator cap. To be honest I think it was a load of bull**** and their lazy mechanics just did not fix what was wrong the first time round.
I hate dealing with dealers but with warrenty work it cannot be avoided I guess.
Mine did that, when I had it dynoed had 300 miles at that time. And the dyno operator says it is overfilled filled from the factory. It happened again when I first took it the track, that was back in march, temp was around 70ish. I didn't do anything about it. Now I am pullied and supposed to be running hotter
(15lbs psi) from my autometer gauge and it has not come back.
I've had that issue for somtime now. Track racing exacerbates the problem and has forced me in to "Limp Mode" more than once.
I have all the mods to reduce the heat issue and I am having the last one I can think of or 2nd to the last one, installed next week. That being the Vortech after cooler mod that holds about a gallon more intercooler fluid. The very last one is the fender vent kit that Kenny Brown is currently redesigning.
If those don't do it then I guess I'm screwed. I'll just have to quit track racing.