Mitsubishi Repair: 96 Eclipse Over heating, radiator cap, temperature gauge

Question
I just recently bought a 96 eclipse 2.0 non turbo automatic. I noticed that the heat was not that good in the car so i replaced the thermostat to see if that would fix the problem. It did fix the heat problem but now I noticed a few other things. I noticed that the temperature gauge does not ever go up or down. I was driving the car today and it drove fine but when i got to where i was going noticed white smoke/steam coming from the hood. I checked the gauge and that's when i realized it did not work. I then got out and checked and under the car was a medium size puddle of coolant. Where could this be coming from? the water pump as the puddle was on the passenger side of the vehicle. Why else could be causing it to overheat as the hoses appear to be fine so should not leak there. What can i check to get the temperature gauge working again? Thanks for nay and all advice.

Answer
Darrell,
Coolant is under high pressure once it heats up, and even the slightest gap or rip in a hose can cause it to leak.  A worn water pump can also leak.  The manufacturers of water pumps put in a weep hole, which will leak coolant slowly to indicate to the operator that the pump needs replacement.  Other areas to check are a around the heater core hoses, radiator cap, and overflow hose and tank.  Your mechanic should also inspect the sending unit and electrical harness near the thermostat housing.
Good luck!