Mitsubishi Repair: Temp gage bobs when gas is accelerated, speed levels, mitz

Question
For a couple of days now the temp gage on my 2003 mitz eclipse gts has been going up to close to the hot level when I accelerate from a low speed and then when my speed levels off it goes back down and bobs at the normal range for a couple of seconds before stablizing.  My husband checked the coolant and it was empty so we filled it up.  I then took it for a test run and it was still doing it.  I drive 2 hours a day round trip to and from work and my car has 125,000 miles on it.  What do you think could be wrong? Thanks

Answer
Courtney: You might have a leak in your system, so you want to have that checked out. Or the water pump could be going out on your car. Again you need to have that checked out as you do not want to be stuck on the side of the road. So please get the car into a shop and have this checked out. Hope this helps and God bless: Linda