I've seen it mentioned before that these have two sensors. I've ordered a Bentley manual but would like to get progress on fixing the car asap. The water temp gauge sometimes doesn't work or drops out completely. I'm still getting reliable water temp readings via OBD (scangauge). Must be two different sensors- the strangest part is that when I see temps over 200 on the OBD, the gauge on the dash goes out- then comes back when it cools slightly and temps drop back to the 190's.
Can anyone tell me which sensor it is and where it is located? Extra points for the part number so I can get one ordered up.


Had two episodes last night, hundreds of miles from home, where it acted as if it was fuel starved. Died once at highway speed, restarted and went a short while before sputtering. Couldn't go above 15mph- no MIL illuminated, no IBD codes. Was smokin when we stopped at that point- suspect transmission over heat, but no warning lamps etc. Smoke didn't smell of coolant or engine oil. Cooled off a couple hours and made it the last 250 miles, but driving much slower and gentler.

02, 3.0 A6 w/115K miles. New factory engine at 90K, new trans at 40K.

 

It sounds to me like you had a serious incident. Just guessing, you had a thermostat stick shut. If you have a guage problem on top of it, you could lunch the motor quick! Get an expert to look into this if you don't know where the parts are. There are two sender elements, one for the ECU in the water pipe behind the cylinders and another for the guage and I don't know were it is unless it's a part of the other sender since there are four wires to it. I looked for it in the wiring diagrams on Alldata and gave up. Sorry.

 

I'm no stranger to cars and I also had it checked out by a good mechanic, although none of us have the VAGcom (yet). As far as we can tell, the transmission overheated. It gave no errors either in OBD or on the info display, but it appears it may have shut itself down as a protective measure. It hasn't skipped a beat since, although that temp sensor issue needs to be fixed- but that's a commonly known issue that I doubt is related to the episode on the highway.