i have a 2004 audi a4 with a 1.8t and sometimes the temp gauge goes down to cold when i have be driving for a while and it should be warm.if i turn the steering wheel sometimes it will work and sometimes it does not work... im am not sure if it is a wiring problem or the sensor problem..

 

is your coolant temperature sensor.

http://www.audiworld.com/tech/eng66.shtml