This is a NA 93 940 with 260k miles.

I was driving at a steady clip on the freeway until I noticed the check engine light. I glanced at the temperature gauge and it was pegged past the red. I immediately pulled onto the shoulder. The car was running just fine. When I cut the engine I could hear coolant percolating from the engine compartment.

I had it towed home. I was without extra coolant (what was I thinking?) and I did not want to chance it. There was very little steam or vapor coming from the engine compartment. A little bit from spray that must have cleared the reservoir. The heater valve is original and intact. I figured that it must be the waterpump as it was about due for one so I changed it out when I got the car home.

There was no visible problem with the old pump, and there seemed to be little play in the bearings and only slight discoloration from the weep hole. I filled the cooling system and started the car. It warmed up fine and I let it run for about five minutes before I took it for a test drive.

The temp gauge was a little on the high side, to the right of the middle, but only slightly different from normal for this car. I took it for a spin, say about an eighth of a mile, and it pulled back up and past the red. There is no oil in the coolant and no foam in the oil.

I let it get cool enough to drive back to the house and topped off the coolant, making sure to try to purge any air from the system. I left the cap on the reservoir a little loose and took it for another drive.

I got further this time before it went back in the red again. Then I took it home.

Are these symptoms consistent with anything that I can repair simply and quickly?