I replaced the fan last week. I bought the entire Bosch (OEM) assembly for $175 + shipping. It took three hours accessing the fan through the wheel well, using the Bentley Manual and Pedro's Garage guides. It's not a complicated repair, the hardest part is getting the bumper support on and off.
I was waiting for the temps in my area to rise again, it was 86° F today, so I did a test drive. I drove for about an hour, and the fan was the cause of all my problems. Without using my manual high speed fan switch, I was running between the 8 and 0 in 180. With the high speed fans it dropped to 180. Still not 100° F outside like when it originally overheated, but I am confident I have resolved the issue. I am amazed that losing one fan caused my coolant temps spike so much.
