The car was running fine until I turn on the heater. Next it begun to overheat, reaching 3/4 of the scale, just below the red zone (driving slow). I was close to home so 10 minutes later I left the car parked.
Next 2-3 days it works fine, 100+ miles without problems. Then the problem showed again. I stopped, lift the hood, and the fans are not working even with the temp going up. Turning the A/C on started the fans, temp go down to expected levels.
The coolant levels are normal and steady. It seems that the fans have an intermitent fault.