why is my 1993 ford e 350 running hot

Sounds like the dip tube on the translucent reservoir has fallen off~

First, check the level in the coolant reservoir. Make sure it is between the full cold and full hot lines. Next, when last was the cooling system serviced? If it is over 2 years, have the cooling system flushed and filled. While you are at it, install a new thermostat, and change all the hoses. That means upper and lower rad hoses, heater hoses and the water pump by-pass hose. Have the flow checked as well. Make sure the water pump is providing sufficient flow. Change the rad cap at the same time. Do all that, and you should be good to go. If the rad hoses are more than a couple years old, throw on new ones at the same time. The labour will be next to nothing, and the belts themselves are not expensive.

After you check the coolant level and before you spend any money, I recommend that you take a good look at the radiator and condensor. Is it full of debris? Look between them too. I would check the operation of the engine cooling fan (Thermocoupler), does it engage when the engine gets warm? You can tell by listening to it "roar" when it draws air through the radiator after it warms up. How does the vehicle run? If it runs rough, a compression check may be in order. This will indicate a Head Gasket or other internal concern as will water in the engine oil. If you warm up the engine (2500 RPM for 3 minutes), does the coolant flow? Both the Top and Bottom Radiator hoses will be hot if the coolant is flowing. The top will be cooler than the bottom if the thermostat is stuck closed. Checking these things will give you a fairly accurate diagnosis of why your engine overheats - or you can throw money at it until you get lucky.

Mike and tracy right on target guys. Its nice to actually read a diagonosisthat doesnt sound like its out of a sci-fi novel