I have a 2001 Audi S4. Last fall, I had maintenance performed on my car, and the shop accidentally, cracked my front fender. They told me about it and replaced it without any issue. However while replacing it, they took off and put back on my front bumper, where my ambient (outdoor) temperature sensor is housed. But they forgot to replace the sensor in the bumper, and it remained dangling below the undercarriage, and eventually was torn off while driving.
I did not notice anything incorrect for quite some time, but I started to realize that whenever it was raining (or the roads were wet), the temperature sensor dropped about 3F degrees per second, reaching -58F.
While not a big problem, this affected the heating and air conditioning air temperature. I started using a new shop that specializes in Audi's that is fantastic, and found the problem, and replaced the sensor and its wiring. The sensor now works fine in the rain.
However the sensor does not work all the time. Sometimes I will be driving, as I did recently from Durham, NC to Washington, DC, and between 2-3 hours into the drive, the temperature sensor drops from the current temperature of 80F to -58F, and then corrects itself, slowly going from -58 to the outside temperature. This takes ~6 minutes. A few minutes later, it does it again.
It only does this complete cycle twice. I am thoroughly confused on what could be happening. It stops working without any change in temperature or the weather. Any suggestions on how to resolve this weird outdoor temperature sensor issue?