My 2007 Ford Mustang with 95,000 miles has a problem. When I went out yesterday and I was at the drive-through I noticed that the gauge was slowly moving into H. I quickly left the drive-through line and pulled over to the side and waited a few minutes. Luckily I was only a few blocks away from home. I drove the car back home, but I noticed that the gauge was in the middle and was slowly trying to go up to H , but then came back down.

I made it home safely. When I got into my garage, I popped the hood to check the coolant tank and it was empty. There were no leaks on the ground or anywhere in the engine. There was no smoke anywhere and the car did not overheat, but the gauge was slowly going to H. I called my mechanic who was completely booked. He said to bring it in on Monday. It was pretty noisy in his shop, but he said I could be one of two things. The only thing that I heard him say that it could be the thermostat that it could be stuck or something like that.

What do you guys think it could be? What kind of price am I looking at roughly? This is terrible that it had to happen on the weekend as I still have to run a few errands. Would it be safe to drive a few blocks in the neighborhood? I could fill the coolant tank with water or coolant (which I have to buy). Even if I fill it, who knows if it’ll be eaten up right away or not.