87 260e coolant problem

[LordBeastington]

Ok, I have had my 260e for a long time with no problems. IT has somewhere over 200k miles. Recently, the coolant light has been coming on in the mornings so I constantly put in coolant. Sometimes every morning and sometimes every month. Today I got in a began driving and noticed my temp was 3/4 way to 120. I quickly pulled over because the coolant light had been on earlier but went off after a few minutes of running. I thought maybe it was low. I popped off the cap of the reclamation tank and a fountain of coolant went everywhere. The coolant was cold! Then, the temp went back to normal. Any idea what happened and what is going on?