Hi.Not long had this 1.7dti 03 reg Problems with my temp guage. It does not move. Have read posts regarding stat etc so have changed the stat and coolant temp sensor but still no joy. I have only ever seen it move once (with old sensor) Heaters do work but take a while to heat up. I have noticed that the coolant in header tank starts circulating as soon as I start the car and there is a kind of misfire when the engine is cold but disappears after about 10 miles driving when engine warms up but still no temp guage. I have done pedal test but light just flashes continually so i assume this means there is no fault codes.