I realize this has been discussed a million times, but I'm wondering if anyone has a similar issue and has successfully resolved a mysterious overheating issue. 98 2.3 CL, manual transmission, overheats in heavy stop-go traffic. I have taken it to my mechanic twice. The first time he couldn't replicate the issue, but replaced the thermostat. It happened again a week later, he said he'd check it out for free so I dropped it off the next morning. He drove it around, let it idle, drove it around, let it idle, everything works as they should - fans come on, car didn't overheat, water pump is good, fan motors good. I picked it up at lunch and then after work it overheated AGAIN. I called him up when I got home, suggested turning on the heater when it happens, pull over if I have to, he'll look at it again tomorrow, drive straight to his garage after my commute. What could he be missing?

 

Usually it's the thermostat, if that isn't the issue, usually it's a fan relay