I suspect this has been posted before, I did a search but didn't come up with too much about it. I have a '93 B250 Ram Van with 207,000 miles on it. 360 engine. It runs and drive great for an old van with so many miles on it. It was owned by a school district so it got regular maintenance.

It has been running hot for two summers in a row now. Winter, not so bad. Finally one day it got very hot and as I was turning around to park it and shut it off, the upper rad hose blew. After several hours letting it cool off I got it home and replaced the hose and thermostat. It still ran a bit hot but not as bad as before. I had a minor leak from somwhere (but now I think it was from the overflow tank) so one day I got the hairbrained, stoopid idea to put in some solder seal gunk stop leak crap. Immediately, it overheated to the red zone again and I had to limp it home over the course of three days! drive a ways, shut off and leave it. go back and drive a bit more, shut off... you get the idea!

Now, it gushes water out of the radiator inlet like a geyser while running. temp is erratic. It will run cool when first started, then the gauge goes up slowly then suddenly jumps up to halfway or more. Seems to be losing a lot of water, but I can't really tell from where. Absolutely NO white smoke out of exhaust, no sign of coolant in the oil, or vice versa. Do I have air in the system, a plugged or defective thermostat or blown head gasket?? I plan to remove the thermostat and flush the system again in a couple of weeks. No, I 'm not driving it right now, thank goodness I have another car.

 

The radiator is plugged, replace it and you should be running cool once again.