Originally Posted by millseyent
It is overheating though, i get the amber then red warning symbols, my coolant temp shoots up to 120+ deg C, but after shutting the car down for about 1 minute the temp drops down to around 100 deg C and the fault clears.
Everything points to it being the coolant sensor or the pump, but BMW have said they are fine, so I am at a loss as to what else it could be
What is your mileage, and how old is the car? Looks a lot like a failing water pump to me, as this is exactly what happened to me. Could also be a failing fan. So you need to buy a code reader like the peak scan tool, and pull the code to find out what component is wrong. Guessing at it, isn't the right approach.
E90 335I: FBO +wavetrac LSD
E92 M3: K&N, Rouge Engineering Pulleys, Macht Schnell Test Pipes, Evolve Tune, Pagid S, V1