In late March I noticed that the coolant gauge would go to cold after driving for a few miles. If I stopped, shut off the car, and then restarted it would run really rough. Furthermore, it was hard to start. A trip to my local auto parts store revealed that with a diagnostic sensor, that the onboard computer was sensing that the engine temperature was at 84 degrees, even though the car had been running for nearly a half hour. The guy at the store believed that the cooling sensor was malfunctioning, and this was causing the engine to run and start rough.