This has been happening intermittently for a little over a year now. When sitting in traffic, my car begins to overheat.
I’ve had two different mechanics look at it - the first swapped out the radiator cap.
The second said my coolant levels were low, but he pressure tested the system and found no leaks. He recommended I check my levels before taking long trips - so this weekend, before driving 380 miles to Phoenix, I checked my levels. They were a bit low, so I topped everything off with coolant and everything was fine on the drive out.
On the drive home, however, stuck in traffic, the car began to overheat. I pulled over and checked the reservoir and it was mostly full of coolant, but I added a little more, let it sit for a while, and then made my way through the traffic and home.
Also, I tested the fan, and it comes on.
Thoughts on what this might be?