Finding Coolant Temperature Sensor (A4)
This is what I used for my Passat and A4 1.8T (04's). Don't know about the 03, but both of my 04's have the puck valve and piping in the way. Get rid of the ine time clamps, and get new ones. Remove all of that stuff and you should see your green sensor. Either go to Autozomne for the part (~$7) or online vendor or dealer. Do not rely on the part numbers in the write up. I hope your not one of those Audi snobs. My B6 has almost exactly the same issues as my B5.5 Passat (just a little later in miles). The cars are so similar it's funny. Coils, gaskets, countless bulbs, wheel bearings.....




