Quote Originally Posted by Valdelisbmw
Intake Air Temperature Sensor relocation on BMW E39 M5
The first is the air intake temperature ready taken by the ECU. The factory air filter / intake system has a major flaw from the factory. The air intake temperature sensor is located inside the mass air sensor housing which sits directly infront of the radiator. Due to the nature of modern temperature sensors, the sensor becomes heatsoaked and sends an artificially high reading to the engine management system. The ECU then retards ignition timing and adds fuel which result in less power.
To avoid this we reloacate the air intake temperature sensor to a more suitable position where it will have a true reading of the air intake temperature.
More read here http://www.evolveautomotive.com/engine-ecu_663/tuning-packages_938/

and few pictures of how it was done
Hi Val.

Thanks for this post. We need more stuff like this!! It can't be all cool looking cars! The oily bits interest me the most I'm curious to know if your pics are before or after? If after where was the sensor located before hand?

Is this a common issue across other models or just specific to the m5?

Thanks!