Ad my first problem on my 98 GT the other day. Pulled out of the driveway went to the gas station and left the car running while I went in and as I was leaving noticed the car was blowing cold air instead of warm and looked at the temp gage seemed fine and by the time I was able to get1/2 mile down the road temp gage was at in between the a and l on the gage so I turned around and went back to the house and as I pulled in my driveway steam was rolling from under the hood and antifreeze was everywhere. Figure it's the t.stat so haven't had time to do anything with it till tomorrow so getting a 180 degree t.stat and going to flush the whole cooling system will be back once I did that hope that fixes everything

 

It could also be coming from one of the hoses too. The thermostat design on these cars blows as far as I'm concerned. I've got a slight crack on the intake where the thermostat is housed. So to fix my water leak, I'll have to replace the intake manifold. Good job Ford!

For now, some stop leak is doing the job wonderfully, and hopefully I'll get around to replacing it sometime this year.

 

Get a pressure tester or take it to a shop to have them pressure test your cooling system and find all the leaks. Have a customer truck in the shop right now leading from 3 different places on the intake manifold and also from the radiator(granted its a junk chevy). Best to find all the leaks at once

 

Got mine fixed Saturday morning it was the t.stat thank god!!!! And not only did I replace it was actually cheaper to get a 180 degree t.stat rather than the oem 192 so got it to run cooler than stock and for a better price been a good weekend for this mustang owner!!!!