I had the same thing happen on my car with the water pump. Yellow temp then a few seconds later red and limp mode. It ended up being the water pump. I asked the dealership how much it would of been if I wasn't under warranty and they said about $1000-$1250 depending if nothing else is wrong. Lucky I was under warranty.
Tischer seems to have the cheapest parts if your going to do this yourself or get the parts and have someone do it.
New - 2013 - 320i - 15% Tint - Future Mods ( BMS Tune, Suspension, Wheels, Exhaust)
Sold - 2007 328i (3-Stage Manifold - BMW Perf Intake w/Scoops - Powerbox - Magnaflow Exhaust - MMW Headers - KW Street Comfort - VMR 701s 19' w/M3 offset - BMW Strut Brace - 330I Brake Conversation - 5% Tint All Around - 8K HID Fog Lights -Angel Eyes)