Can I get home? Overheating '97 850 GLT

[acrocentric]

So here's the story:

1997 850 GLT w/ 150k miles.

I haven't been driving her for the past 3 weeks, but has been running fine up til then.

Had to jump battery to get it started, and took 2 short trips last night without a problem. Topped off the oil and coolant which were both a little low.

This morning, started fine, and I began to drive down the highway to my job which is roughly 50 miles away. On cue, 25 miles into the drive, the temp guage rather suddenly starts pushing towards the red. I turned on the heater and pulled over to the breakdown lane, letting it cool for a bit, then went under the hood to check the coolant levels. As expected, the coolant was under high pressure and shot out when I unscrewed it, so I let it overflow for a few seconds, then screwed it back on, not very tightly.

I started it up again, and drove slowly up the breakdown lane for a minute or two, and again the temp guage rose up towards the red, so I pulled over again and went to make sure the coolant wasn't pouring out of the cap. It wasn't, and the level seemed to be OK. I figured I'd try one more time before calling in for backup (although neither the GF nor the mom would likely be interested in coming to pick me up this early in the a.m...). This time, I started out slow in the breakdown lane, no sigh of overheating, and again I kept the heat on - strangely, whlile hot air was directed through the defroster vents which I had selected, COLD air was being blown out through the dashboard vents (which usually spill over the A/C or heat unless I close them). Not sure if this means anything, but struck me as weird.

Anyway, after that point, the car didn't even begin to overheat again, and I made the rest of the 20 miles or so without a problem.

Any suggestions for a diagnosis on this? Would you expect the car to be OK to drive home?

My only thought was that it could be a thermostat problem, which was stuck closed when I was overheating, but somehow unstuck itself. Has this type of thing happened to anyone? How urgent (i.e. before my drive home, or after...) must this be fixed?

Thanks for any help! You guys are great.

[chuckcintron]

Don't drive it the way it is. If it were me, I'd take the couple of tools I need back to the car and a new thermostat, 50/50 coolant and do a roadside (or parking lot) repair. Not much else that could be wrong with it to drive the temp up like that unless the system is so crudded up that the radiator itself is clogged.

-Chuck