I've been reading the forums to try and ascertain the cause of my car slowly leaking coolant, resulting in the temperature light illuminating. After a quick re-fill of water, the problems persists. There is no signs of water inside the car, including both front footwells, so I don't suspect the heater matrix. There is also no sign of water leaking from underneath the car/radiator area. Both top and bottom pipes to the radiator are both hot after a good run, so don't suspect the thermostat. I've also checked the oil and there are no signs of foaming type substance, so don't suspect the head