While running the car in the driveway to bleed the cooling system, at some point the temperature started going up towards the third mark on the gauge and did not cool down even with the heat running full blast. Of course, that could be due to air in the system but I also noticed the fan wasn't spinning. With the car turned off, I tried to spin it by but it was stuck. A firm push broke it loose, and after starting the car it ran and the temp started going down quickly.
Driving around after this at first the temperature stayed at or below the center mark, but after parking and then going again the temp started passing the center mark and when I pulled off the fan was again not spinning, and giving it a flick loosened it up and the temp again started dropping immediately. So it seems like the fan clutch is busted, and while it is straightforward to replace it does require some special tools.
At first I just got a new fan clutch, but one of the bolts rounded off when I was removing the fan; a good excuse to replace the whole thing (and buy some new tools to avoid that happening next time). I also didn't need to use the water pump pulley holder to get the fan clutch off or back on again, just the fan clutch wrench to get way down in there.
Fan clutch part and tools:
fresh new oem fan
the old fan had p/n 1272544420
fresh new fan p/n 11521273086
@frijole :: @fe30lix_ :: #fever