Originally Posted by Superd
The coolant cant physically heat up and cool down in such a short period of time so it sounds like a faulty temp sensor. Should be an easy fix for the dealer.
When they told me that it was definitely overheating, I brought this up as well. Which is what made them change the temp sensor even though it was testing ok.
I don't think they are taking a true temp reading, and just going off of the car's warning system, but I don't know that for sure. The whole thing seems really weird.