I've just got a 406 LX (petrol) off my parents and there is something seriously wrong with the temperature control: during normal driving the engine runs cold (about 80c), in traffic it heats up (about 100c). I flushed the radiator yesterday and noticed the fan not kicking in, which would explain part of the problem, but why is it running cold? My dad changed the thermostat before I got the car, which I thought would have fixed it - could he have fitted it wrong?