Ford Repair: Faulty Temp gauge, blown head gasket, coolant water

Question
Hi, I bought Ford Contour SE 95 2 months ago in running condition. 3 weeks ago I drove car 2.5 hrs continously and when I stopped the car its water tank was boiling (I didn't notice temp gauge while driving). then in next few days whenever I drove car, It temp came to red zone within 7-10 mins of drive. my friend suggested me to change thermostate and water pump. I changed both and found broken water pump. after that car was good. but 3 days ago I was driving it, and suddenly the Temp gauge moved to red zone and then dropped right next to red line. now its hanging over there and I'm driving car in the same situation. Please tell me what I need to do. I asked my friend he said no idea about this.

Answer
Hello Soofi,
    The first thing to do in an overheat situation is to verify proper coolant level, and make sure it is circulating through the radiator when the temp. is high enough to open the thermostat(about 190 degrees). Basic possible overheating causes:
low coolant
water pump belt slipping or impeller gone
thermostat stuck
radiator scaled up inside or clogged/not efficient enough
recovery tank cap not sealing to bottle
blown head gasket
air bubbles trapped in system
    Those are some possible causes to check. If you can verify that the engine is not actually overheating, then you can start diagnosing a gauge problem.
   I'm sorry I didn't get back to you sooner. I had to wait for my lunchbreak at work. I hope this can help you a little. Good luck.  Shaun.