I have a 2005 infiniti g35. the first problem arose
when I was driving my car not 5 min and the temp
gauge read pretty much to the top. it started
fluctuating from normal to hot. then the next day it
was fine no problems. next time it heated up I
pulled over and all the fans were blowing and I
couldn't feel overheating. the gauge fluctuates but
will read normal for a while I started pushing the
rpms for a bit and the temp stayed normal...
Did you get a check engine light along with the blip in the temperature gauge? I may be wrong, but your Infinity may have a temp sensor and a separate temp sending unit for the dash gauge. I'd check for trouble codes, as usually a temp sensor triggers them.