'91 300CE - blew my radiator tonight and overheated

[rgnprof]

Wife was driving the car home tonight and noticed that it was smoking from under the hood - she got off the highway (was going approx 60 mph at the time) and got the card parked and let it idle for a few minutes - temps started to drop...

I got there just a few minutes later and then the car stalled out - temps had dropped to just below 100C. Anyway, upon opening the hood, the problem was obvious - the top radiator hose was off as the plastic nipple had broken off. I tried to get it back on enough to get home and added some water and pulled the thermostat - car ran for a bit, but I couldn't get it on tight enough to get it home and it blew off again after just a couple of minutes. So I finally called AAA...

Question is how much damage do you think has been done? The gauge was clearly pegged, but I don't think it was that way for very long. Also, I am a little concerned about adding the cooler water to this really hot coolant - hope I didn't blow out a water jacket...

Any way to find out what the damage is short of first replacing the radiator and seeing what happens??

Thanks for the help.
ryan