I have a manual 1998 Pontiac Sunfire. It's a 2 door and has like 129,000 miles on it. I was out of town for a week and half and hadn't driven it for that time. When I got back I noticed the temp gauge kept surging up and down and went into the red a few times. Then one day I pulled into the driveway at work and there was this gurgling sound on the right by the passenger side. I later checked and there was no coolant left. My roommate and I thought it was the thermostat so we replaced it. My car was fine for like 2 and half weeks and the temp gauge stopped surging. Now it's completely schizoid or somethiing and is moving up and down constantly. I've put like 3 jugs of premixed antifreez in there the last 3 days. What's wrong w/ my car?
You have to find where the coolant is disappearing to. It's either an external(outside the engine) or internal(inside the engine)leak. Check under the car after you've refilled it. Also check the carpet under the dash to see if it's wet.
If no problem there then the leak is internal and would need to be further diagnosed.