where the hell is the thermo sensor, the FSM says it is somewhere behind the thermostat cover but i see nothing and Haynes says its underneath the oil filter and i see something there but i dont want to unscrew it till i truly know what it is because with my luck i will break it when i unscrew it (and i am not talking about the oil pressure sending unit). so where is the thermo sensor??? my car is an S5 turbo 1990.

just to make sure we are talking about the same thing its the coolant temp sending unit?? right?page 106 diagram 10.1?

step 1, throw away the haynes, its crap



step 2, the coolant temp sensor for the ECU is in the back of the water pump, its green. sensor for the gauge is under the oil filter

agreed its the one directly under the long threw bolt for the alt. its green with a spring clip retainer similar to a injector plug. there is a sensor , a single wire sensor under the filter pedistal aswell but the one you are after is the one on the water pump.

back of the pump, how hard is it to get too

pull the alt off and bust it with a 19mm that is if thats the one you are talking about?? it goes into the t-stat housing and is right under the t-stat