engine problems

hey all, im gonna have my teg serviced soon, but i was just wondering if anyone could maybe help before i do…just lately, when im driving, when i try to accelerate too hard, or accelerate when im going up a hill, or even just take off, more often that not, the engine sort of splutters, like the pistons are misfiring, then after about 2 seconds it will stop then and run smoothly again…but then after i change gears again, the same thing happens…its kinda scary when im taking off to turn across trafic, and it happens, and i have shit acceleration for the first couple of seconds…also, i dont know if this is related, but i just noticed today, then whem im idoling, after about 10 seconds, the noise of the engine changes and the temp gauge rockets up to close to the hot line…but when i get driving again, it goes back to where it normally is within about 5 seconds… it seems to be moving too fast to be acurate, and when i got home and popped the hood the engine seemed at normal temp, so maybe its the gauge…does any of this sound familiar to anyone? thanx for any help