Hi guys, I've been noticing my temperature rising during enthusiastic driving.     Driving normally my temperature sits just below half.     I can drive enthusiastically through 1st, 2nd, 3rd fine, then in fourth and fifth when accelerating for long periods (presume putting the engine under the most stress) the temperature creeps above half, its been at nearly 3/4 before ive noticed it in the past.  Now as soon as i see go past half I back off.     Basically cannot go flat out in fourth or fifth on a straight run as the temperature keeps rising, don;t know ho much it would rise to if I kept on it but don't want to find out     Any ideas?