E30 Zone

hi i bought a 325 engine but its missing the water tem sensor in the top of the housing at the front of the engine, were the radiator pipe comes of.

can any1 tell me what the sensors for? is it for the gauge? is the sensor brown? and is it 1 pin ?

There are two temp sensors fitted to an M20 thermostat elbow. The two pin one is for the engine ECU, and the engine will run extremely rich without it. The other one has a single pin and is for the gauge. The same sensor is fitted on many other BMW's.